HomeMy WebLinkAboutSR - RES-10936 - PART 1 APPENDICES 2015 URBAN WATER MANAGEMENT PLAN �
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UWMP Checklist
This checklist is developed directly from the Urban Water Management Planning Act and SB X7-7. It is
provided to support water suppliers during preparation of their UWMPs. Two versions of the UWMP
Checklist are provided—the first one is organized according to the California Water Code and the second
checklist according to subject matter. The two checklists contain duplicate information and the water
supplier should use whichever checklist is more convenient. In the event that information or
recommendations in these tables are inconsistent with, conflict with, or omit the requirements of the Act or
applicable laws, the Act or other laws shall prevail.
Each water supplier submitting an UWMP can also provide DWR with the UWMP location of the required
element by completing the last column of eitherchecklist. This will support DWR in its review of these
UWMPs. The completed form can be included with the UWMP.
If an item does not pertain to a water supplier,then state the UWMP requirement and note that it does not
apply to the agency. For example, if a water supplier does not use groundwater as a water supply
source, then there should be a statement in the UWMP that groundwater is not a water supply source.
Checklist Arranged by Subject
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�t�g����rj Every person that becomes an urban water Plan Preparation Section 2.1 Section 1.1
` supplier shall adopt an urban water
management plan within one year after it has
become an urban water supplier.
"lQ���d��, Coordinate the preparation of its plan with Plan Preparation Section 2.5.2 Section 8.2
other appropriate agencies in the area,
' including other water suppliers that share a
common source, water management
; agencies, and relevant public agencies, to
the extent practicable.
1�4� Provide supporting documentation that the Plan Preparation Section 2.52 Section 8.1
' water supplier has encouraged active and
involvement of diverse social, cultural, and Appendix E
' economic elements of the population within
the service area prior to and during the
preparation of the plan.
'1�"I��tj Describe the water supplier service area. System Section 3.1 Section
Description 1.3.1
1��3�1�a�j Describe the climate of the service area of System Section 3.3 Section
' the supplier. Description 2.2.1
106�"#��� Provide population projections for 2020, System Section 3.4 Section
2025, 2030, and 2035. Description 2.2.2
'it�831��t) Describe other demographic factors affecting System Section 3.4 Section
' the supplier's water management planning. Description 2.3
'Ifl�3"!(�E� ; Indicate the current population of the service System Sections 3.4 Section
area. Description and and 5.4 2.2.2
Baselines and
Targets
'��6�i'���}��� � � Quantify past, current, and projected water System Water Section 4.2 Section
use, identifying the uses among water use Use 2.3.1 and
sectors. 2.4.3
"1�#B�1(�j�3��� ; Report the distribution system water loss for System Water Section 4.3 Section
the most recent 12-month period available. Use 2.3.4 and
Appendix H
1tl��'�,1��tj Include projected water use needed for lower System Water Section 4.5 Section
' income housing projected in the service area Use 2.4.5
of the supplier.
1t��fi��i��4(b) Retail suppliers shall adopt a 2020 water use Baselines and Section 5.7 Section
target using one of four methods. Targets and App E 2.5.2.1
�pgpg;�(�� ` Retail suppliers shall provide baseline daily Baselines and Chapter 5 and Section
per capita water use, urban water use target, Targets App E 2.5.2.2
interim urban water use target, and
compliance daily per capita water use, along
� . .: . �� with the bases for determining those
' estimates, including references to supporting
��� data.
.._. �
,����� ;;. ' Retail suppliers' per capita daily water use Baselines and Section 5J2 Section
' reduction shall be no less than 5 percent of Targets 2.5.2.2
` ` `' base daily per capita water use of the 5 year
baseline.This does not apply if the suppliers
base GPCD is at or below 100.
��������„ � Retail suppliers shall meet their interim Baselines and Section 5.8 Section
:' target by December 31, 2015. Targets and App E 2.5.2.2
,
���,�i���"� If the retail supplier adjusts its compliance Baselines and Section 5.8.2 Section
GPCD using weather normalization, Targets 2.5.2.2
economic adjustment, or extraordinary
events, it shall provide the basis for, and
data su ortin the ad'ustment.
'����-,;�' ."_ �� � : Wholesale suppliers shall include an Baselines and Section 5.1 N/A
assessment of present and proposed future Targets
,.
measures, programs, and policies to help
�`'� �� ��� their retail water suppliers achieve targeted
water use reductions.
'���� �� � �� Retail suppliers shall report on their progress Baselines and Section 5.8 Section
' in meeting their water use targets. The data Targets and App E 2.5.2.2
' shall be reported using a standardized form.
� � �.� �
Identif and u
�'�������� ,; y q antify the existing and System Supplies Chapter 6 Section 3��������
� . . �
. ; ' � , � planned sources of water available for 2015,
2020, 2025, 2030, and 2035.
'����. ���� �' �� Indicate whether groundwater is an existing System Supplies Section 6.2 Section 3.3
or planned source of water available to the
��� supplier.
'I�"���� � ��� Indicate whether a groundwater System Supplies Section 6.2.2 Section
management plan has been adopted by the 3.3.2.1
water supplier or if there is any other specific
authorization for groundwater management.
Include a copy of the plan or authorization.
E
�`����k�;� Describe the groundwater basin. System Supplies Section 6.2.1 Section
3.3.1
'������� ��� Indicate if the basin has been adjudicated System Supplies Section 6.2.2 Section
; and include a copy of the court order or 3.3.2
decree and a description of the amount of
° water the supplier has the legal right to
, pump.
7������� °�i For unadjudicated basins, indicate whether System Supplies Section 6.2.3 Section
°'� or not the department has identified the 3.3.7
M; basin as overdrafted, or projected to become
: overdrafted. Describe efforts by the supplier
� to eliminate the long-term overdraft
������ condition.
,
'�� �� ,� Provide a detailed description and analysis System Supplies Section 6.2.4 Section
�� of the location, amount, and sufficiency of 3.3.6
groundwater pumped by the urban water
supplier for the past five years
1063'��b�{�4� Provide a detailed description and analysis System Supplies Sections 6.2 Section 3.3
of the amount and location of groundwater and 6.9 and 3.4
that is projected to be pumped.
'11�'����` Describe the opportunities for exchanges or System Supplies Section 6.7 Section 7.2
transfers of water on a short-term or long-
term basis.
�`t1H3���� Describe the expected future water supply System Supplies Section 6.8 Section 7
projects and programs that may be
undertaken by the water supplier to address
water supply reliability in average, single-dry,
and multiple-dry years.
1�#Eii���h) ` Describe desalinated water project System Supplies Section 6.6 Section 7.4
opportunities for long-term supply.
"1i������ ' Retail suppliers will include documentation System Supplies Section 2.5.1 Section 3.4
i that they have provided their wholesale
' supplier(s)—if any-with water use
; projections from that source.
'����) Wholesale suppliers will include System Supplies Section 2.5.1 N/A
documentation that they have provided their
urban water suppliers with identification and
' quantification of the existing and planned
sources of water available from the
wholesale to the urban supplier during
various water year types.
10�$ For wastewater and recycled water, System Supplies Section 6.5.1 Section 6.1
coordinate with local water, wastewater, (Recycled
groundwater, and planning agencies that Water)
operate within the supplier's service area.
1A6�3(�) ' Describe the wastewater collection and System Supplies Section 6.5.2 Section 6.2
treatment systems in the supplier's service (Recycled
' area. Include quantification of the amount of Water)
wastewater collected and treated and the
' methods of wastewater disposal.
1p$����� : Describe the quantity of treated wastewater System Supplies Section Section 6.2
that meets recycled water standards, is (Recycled 6.5.2.2
being discharged, and is otherwise available Water)
for use in a recycled water project.
90����Cj ', ' Describe the recycled water currently being System Supplies Section 6.5.3 Section 6.3
' used in the supplier's service area. (Recycled and 6.5.4
Water)
1U��t�) ` Describe and quantify the potential uses of System Supplies Section 6.5.4 Section 6.4
recycled water and provide a determination (Recycled
of the technical and economic feasibility of Water)
' those uses.
1t1E��3�+�� Describe the projected use of recycled water System Supplies Section 6.5.4 Section 6.3
within the supplier's service area at the end (Recycled and 6.4
of 5, 10, 15, and 20 years, and a description Water)
of the actual use of rec cled water in
comparison to uses previously projected.
�x.
't�t���� �� �� Describe the actions which may be taken to System Supplies Section 6.5.5 Section 6.� �
encourage the use of recycled water and the (Recycled
' projected results of these actions in terms of Water)
' acre-feet of recycled water used per year.
„�����j Provide a plan for optimizing the use of System Supplies Section 6.5.5 Section 6.5
recycled water in the supplier's service area. (Recycled
Water)
%"���� � ���� Describe water management tools and Water Supply Section 7.4 Section 3.3,
options to maximize resources and minimize Reliability 4.5, 4.6, 6.4
the need to import water from other regions. Assessment
��'f(������'��)� ��� Describe the reliability of the water supply Water Supply Section 7.1 Section 3.7
and vulnerability to seasonal or climatic Reliability
' shortage. Assessment
����'���}(i� Provide data for an average water year, a Water Supply Section 7.2 Section
single dry water year, and multiple dry water Reliability 3.7.5
years Assessment
'�f�'r�(������ �� For any water source that may not be Water Supply Section 7.1 Section
available at a consistent level of use, Reliability 3.2.3, 3.3.,
describe plans to supplement or replace that Assessment 3.7,4
� � . . � source.
��:� � Provide information on the quality of existing Water Supply Section 7.1 Section
sources of water available to the supplier Reliability 3J.2.3
and the manner in which water quality Assessment
° affects water management strategies and ..�.
supply reliability
4���� `� � Assess the water supply reliability during Water Supply Section 7.3 Section
' normal, dry, and multiple dry water years by Reliability 3.8
comparing the total water supply sources Assessment
' available to the water supplier with the total
'; projected water use over the next 20 years.
���������r�d � Provide an urban water shortage Water Shortage Section 8.1 Section 5.2
1���r��1� contingency analysis that specifies stages of Contingency
action and an outline of specific water supply Planning
conditions at each stage.
"�������. , " Provide an estimate of the minimum water Water Shortage Section 8.9 Section 5.3
' supply available during each of the next Contingency
'' three water years based on the driest three- Planning
' �;'>� , .: year historic sequence for the agency.
'�����t���� ��� � �' Identify actions to be undertaken by the Water Shortage Section 8.8 Section 5.4
' urban water supplier in case of a Contingency
° , ° ,. catastrophic interruption of water supplies. Planning
y�{f�����; ' ��: Identify mandatory prohibitions against Water Shortage Section 8.2 Section
' `' ' specific water use practices during water Contingency 5.5.1
� shortages. Planning
�� ��� �,� : ��� Specify consumption reduction methods in Water Shortage Section 8.4 Section
; the most restrictive stages. Contingency 5.5.3
Planning
N'��i����i�: Indicated penalties or charges for excessive Water Shortage Section 8.3 Section `'"
� ; ,,�,
�.�. . �� � �' � �� Contin enc
use, where applicable. Planning 5.5.2
1Q8���'T� Provide an analysis of the impacts of each of Water Shortage Section 8.6 Section 5.6
the actions and conditions in the water Contingency
shortage contingency analysis on the Planning
revenues and expenditures of the urban
' water supplier, and proposed measures to
overcome those impacts.
1f�83��ai��8� ' Provide a draft water shortage contingency Water Shortage Section 8J Appendix D
resolution or ordinance. Contingency
Planning
1i�?��(�) Indicate a mechanism for determining actual Water Shortage Section 8.5 Section 5.7
reductions in water use pursuant to the water Contingency
shortage contingency analysis. Planning
"tfl6�^��{���I� ' Retail suppliers shall provide a description of Demand Sections 9.2 Section 4
' the nature and extent of each demand Management and 9.3
' management measure implemented over the Measures
past five years. The description will address
; specific measures listed in code.
11�t�,3���� Wholesale suppliers shall describe specific Demand Sections 9.1 N/A
demand management measures listed in Management and 9.3
code, their distribution system asset Measures
' management program, and supplier
assistance program.
1t1$�1{�� CUWCC members may submit their 2013- Demand Section 9.5 Section 4
; 2014 CUWCC BMP annual reports in lieu of, Management and
' or in addition to, describing the DMM Measures Appendix J
implementation in their UWMPs. This option
' is only allowable if the supplier has been
found to be in full compliance with the
CUWCC MOU.
1Q�tl�:��a� Retail suppliers shall conduct a public Plan Adoption, Section 10.3 Section 8.1
hearing to discuss adoption, implementation, Submittal, and
and economic impact of water use targets. Implementation
10��1{�T�; ' Notify, at least 60 days prior to the public Plan Adoption, Section 10.2.1 Appendix E
hearing, any city or county within which the Submittal, and
! supplier provides water that the urban water Implementation
supplier will be reviewing the plan and
` considering amendments or changes to the
I plan.
1�1�'!-��M� i Each urban water supplier shall update and Plan Adoption, Sections Section
submit its 2015 plan to the department by Submittal, and 10.3.1 and 8.3.3
July 1, 2016. Implementation 10.4
1fl6�!��j ; Provide supporting documentation that Plan Adoption, Section 10.4.4 Section
Water Shortage Contingency Plan has been, Submittal, and 8.3.3
or will be, provided to any city or county Implementation
within which it provides water, no later than
60 days after the submission of the plan to
" DWR.
1064� Provide supporting documentation that the Plan Adoption, Sections Section 8.1
' urban water supplier made the plan available Submittal, and 10.2.2, 10.3,
: for public inspection, published notice of the Implementation and 10.5
public hearing, and held a public hearing
� ��� � ������ about the plan.
'�8+l� ' The water supplier is to provide the time and Plan Adoption, Sections Appendix E
place of the hearing to any city or county Submittal, and 10.2.1
' within which the supplier provides water. Implementation
�#��G� �� Provide supporting documentation that the Plan Adoption, Section 10.3.1 Appendix F
plan has been adopted as prepared or Submittal, and
modified. Implementation
�t�B�(�� '; ' Provide supporting documentation that the Plan Adoption, Section 10.4.3 Section
urban water supplier has submitted this Submittal, and 8.3.3
UWMP to the California State Library. Implementation
° "I������"�'� Provide supporting documentation that the Plan Adoption, Section 10.4.4 Section 8.2
urban water supplier has submitted this Submittal, and
' UWMP to any city or county within which the Implementation
` supplier provides water no later than 30 days
� ���� after adoption.
' "#t������ � The plan, or amendments to the plan, Plan Adoption, Sections Section
submitted to the department shall be Submittal, and 10.4.1 and 8.3.3
submitted electronically. Implementation 10.4.2
��� .'� �; Provide supporting documentation that, Plan Adoption, Section 10.5 Section 8
not later than 30 days after filing a copy Submittal, and
of its plan with the department,the Implementation
supplier has or will make the plan
available for public review during normal
' business hours.
� • ' •
r� �
Pub�ic:t����ar'��rss��rra �+�k�fi��1�l�ter S�rst�*rti' „ , �1�ak��t�f�ll�n�±���1 .��1t����
�lurr�ber #��rn� �#i��t�r�i�aw�s���5
�������i�d'
���'
CA3010027 City of Orange 36,347 28,643
TOTAL 36,347 28,643
NOTES:
. . . - .
p in�liv�d�t'��1�► ,
O 1+V�ter Su�piier is als�a:a m��`rb�r c�f�i�UU�lU��
� �������li�r is ais4 a mem#�er c�#�#��gi�r�at
ll��t���: Orange County 20x2020 Regional Alliance
❑ Re�ii�1�t�r'�'��r N1�►r�8�;emerrt Pi�l3��t�il�) '
NOTES:
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� ��3��fi-�a�1 W�t'f����� ,
� ��;CtL�..#��1"�''��I�:i'' , '.
• .. •
� L11AtIVIP'��k�1e51#r�.�tt C�1�*�t��`�f��
O UWM�'T�b1��Ar.e in�i��#�+�!�
If Using Fiscal Years Provide Month and Date that the Fiscal Year Begins
_ (mm/dd)
7/1
. -. • . � .. ..
U��� AF
NOTES:
. • � • • • •
•• ♦ '• � M • �• � • • '1
• • �•
MWDOC
NOTES:
. . � . . . . • . - .
� < ,� , � � 3;� { z � �� ; � t � ,,�. �.
, P�+pu�l��a�r� , , ���.�5 �'�� �,C��� ��� ���� �� �
� ,: . ,
����� " 138,987 140,203 143,429 145,735 146,916 146,795
NOTES: Center for Demographic Research,California State University, Fullerton
. • � � • � • ' � . � �
•
i �
1 t I I I I Y • Y.� ! '/'I
'31sq G�Fof7+�Wh lr�t , ,, _
�� +���e��r�h'u��n�+t�t���3 � � � 1�1���tn��fi � �
�Fh�se ar�#he tarrtY��lse�ypcs;th�rt wiJt be " . � ���f31't����@5Ci'i�tl�3t1 �
� p �le@ded� �j '��1�V�1�.'i��r��!'�r��d �R��#�°��
r�sagatzed#�y ri�WUEdata orHFne#Ubfrrittat �� � �
tooi �ri►p t�awtZ list
Single Family Drinking Water 13,176
Multi-Family Includes condo Drinking Water 4,558
Institutional/Governmental Drinking Water 580
Commercial Includes Industrial Drinking Water 9,167
Agricultural irrigation Drinking Water 192
Losses Drinking Water 969
TOTAL 28,643
NOTES: Data from City of Orange billing records.
. • � � - • • ' � . • • � • �
r �M
•- ��r ��e i a i i • -s �
-�•� '!� � I I � � t •J - ., ..
.� r . ,=r������1�'���a���"��i�� ,„j:. i '
M(�y s8�Btirlt USe l�t�t�#�#Ht�s.'s � ��tS'�!'�{��� . �� ; - .
These dre fhe stn�Y Usk i'�+]re#tt�t wilt b� ` ,�',� ��� +��� ; ,����r ��{�' ' '
recognized by the WUEdata ifnll�re tubrrilt#trt
Single Family 12,881 13,571 13,571 13,571 13,571
Multi-Family Includes condo 4,456 4,695 4,695 4,695 4,695
Institutional/Governmental 567 597 597 597 597
Commercial Includes Industrial 8,962 9,442 9,442 9,442 9,442
Agricultural irrigation 188 198 198 198 198
Losses 947 998 998 998 998
TOTAL 28,000 29,500 29,500 29,500 29,500
NOTES: Data retrieved from MWDOC Customer Class Usage Data and Retail Water Agency Projections.
. • � • � ' •
#,,
���� i���� ���J ' �� ��'�� ��+�� . ;
P��������������� ��� � 28,643 28,000 29,500 29,500 29,500 29,500
Ta#rl�s q;-�t at�d�+,�
Recy�l�d�l�ter��►�a�r�i� F'rar�r 0 0 0 0 0 0
Table 6-4
TOTAL WATER DEMAND 28,643 28,000 29,500 29,500 29,500 29,500
NOTES:
. . - � � . . � . - . .
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� �` ��sf�r������t�"��
������
07/2014 2,363
NOTES:
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� � , :: ,..
A�*��w��.1���������d�i�i�'��j�+�tt�rr�*�!`
(f�+efier���t�t�f�r�cs�-�„#�1�".�a'rd�ebcsol�� Yes
�3rop tlawn list(y1'r+7
�f''�v�s° to ab�ve.sta��e s�[��r�a�e r�ainber,m t�e c�#1#ts t�e rt�#�c,w#��e ata�ans r►�the ctides, Sect i o n 4.1
' ardir�a�c�s,�'rF,:���n�rna�tl;�? ; are fc►upd,
Ar�a Lfluv�r#n�am��k+����t.���a�nds�i`��±�t��d!�Pr�j�+�t��r�s�; Yes
`t�ro t�own list fY/►?1
NOTES:
. .
'' • � �� � '�� � • � i � �
„ �. - ��� � t
Bas���ie ` � ` ����Irr���'�ra�> ��i��rr►��d '
�r�Y��r �'�n��+�r � �����
P�rtt��4 �6��*, =. , �`�r�et* �+���7'�r��*
�; 3�,1��� � �� � _ � �
1999 2008 226 203 181
�� :
�' ;��t���, �; 2ooa zoos zza
NOTES:
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s"
���:� ��tA��9�1�T ' `
' A���l ,`������it�rt' ` � �C�'�1!��1� ,
20���P�t� � �"�t�� ' �'���te�
�t���t����r�� '��
�.''��� ��'�� �� �1���'�/I� '��� ���
145 203 Yes
NOTES:
. . . . . . - .
��`ti��`����� � �,. � '"',
Dra�r il�rti�m t��# `! l"t�fi�rn a�r Bas�n 2fl3�3. 2fl1� ��3�� : ;���;4: ;"����
� � May use e�h��c�o#�gary � ' �N�ri^le .���� � � : : � � �:� , : , ..: .. . ���
multip/e rime"s '
Aliuvial Basin Orange County 16,824 13,418 21,125 23,119 20,372
Groundwater Basin
TOTAL 16,824 13,418 21,125 23,119 20,372
NOTES:
_ • � '� 1
� i � • • -
�
������i����t'i�` �s��i�t���� `` ���iW�l�'t�i�C��ed
��r'��� } '��i��.", �1u�� `;: �`r+��rr��t���'- ��;a�`ts�#�t '�it��r�IJWM�'
�� 'V4��ev�r��t � � 1��v��r �
� �s�����` R�c�iVing Ct+11�� '� Alame�� Ar�a?
Coliect�an Agency Callec���!�n 2Ct15
brop liown f�st W�st��TtHC�r ' Orop►aaw++tist
Plant No. 1/
City of Orange Estimated 18,618 OCSD Plant No.2 No
Total Wastewater Collected from Service
Area in 2015: 18,618
NOTES:
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These a're tfre orfty water s�t�pl�t+i�#+��tiries `� �k���l VC�it���. (�,t���
�
tt�ai wtll be recQgn�z�d by tlt��Wkl�dota�rnitne t)rop Uown tisr
submlttot foo?
Groundwater Orange County 2� 3�2 Drinking
Groundwater Basin ' Water
Purchased or Imported Water MWDOC 6,514 Drinking
Water
Surface water Serrano WD 1,757 Drinking
Water
Total 28,643
NOTES:
. . . . . -.
�� ,, , ,� , �,
..
s,� � � .
, -.. , . .. ,
,�
�+�oy nse ea�te��a��p�e ttme� �;�d��+�n���l���� ��'+!� ��= ' � �;'�� � �;��'� ��
77r�e�rre che orrly s+�ers��� '; 1i�tat�t"���K1�' ` " fl���t� ,,
catpgvrtes'thcit wirl;tr�f�ct�rr��+��ib}! ; '' ������r, ;, '�� ���q�� ��`���M��, �!�S��t�t
the tAruEdatc on►ine sa��titit#�e�t � = ` ��'��I�bbe - �'u�i��� F �A�i����{ a?ii�ail�fi��:- �i��i�; "
� 'Vc�lur�+� '�u"'.r��f `:':��I�i�� . Yt#l+�r�.'. �trs�c�r�n�'
Groundwater Orange County 19,600 20,650 20,650 20,650 20,650
Groundwater Basin
Purchased or Imported Water MWDOC 7,200 7,650 7,650 7,650 7,650
Surface water Serrano WD 1,200 1,200 1,200 1,200 1,200
Total 28,000 29,500 29,500 29,500 29,500
NOTES:
. . �
r.
. . . .
. - � - . - .
Qua�#ification of available supplies is not
��'����' ' Cnrnpatible with this table and is provided
�"`�'��' � etsewhere in the UWMP,
c�►feaadvr�eat>�jn
�����,�t�" I fhei+s�ye4rof t� �� LOC2tlOt1�
f�stcrt, w'�rt�rYeA+',t+�'
;r.,r,�ecfye��ar quan#ification of availabte supplies is prQvided
�ram�w�r y�ar, C.l
iyy�,2�,,,��� in this table as either volume on1y,petcent
only,or both.
1�c�i��1��l�t�te ' '�������Supply
Average Y�:�r 2015 100�
Strtgl�-[�ty'��r 2014 106%
Mult�ple-�Jr�t Y���s�;�-Y�` 2012 106%
Mu1t3pl�-��'y Y�"arS��t�'��T 2013 106%
Mul#9p1e-t�ryYB�i's3rt�;Y��r ' 2014 106%
NOTES: Developed by MWDOC as 2015 Bump Methodology
. • • e � • � • • • � . s
x;"�� � �?,� ..s�* a z �, .,
t r4 F �, "� : r :�; '�,�xr : `
�; ��� ��'J ��� �.°", ����� ��
�
. ,,., , ... � ,
, �.
�l�j�k���i,'�t�'���5 ;
����, .� ��� 'tt�b����� ...,' 28,t300 29,500 29,500 29,5t10 29,500
..
����t�d�,���JS "
`�'u�f�#`� �:'��k�����.�� ` 28,QOU 29,500 29,5t30 29,500 29,500
���������" 0 0 0 0 0
NOTES:
. � � • • • � • • • s . •
��3:�
���� ��� � ,,, ��� ' ���� + ��
Supply tot�l5 ' 29,680 31,270 31,270 31,270 31,270
�em��rc�tc�t�ls 29,680 31,270 31,270 31,270 31,270
Difif�r�nce 0 0 0 0 0
NOTES: Developed by MWDOC as 2015 Bump Methodology
. • � • � � � � � - • • � . •
���� ���� ��� ' �� ����
�t�����1��� � °� 29,680 31,270 31,270 31,270 31,270
' ��*�y��",'- ' �l��������� '� 29,680 31,270 31,270 31,270 31,270
' t��er�c� 0 0 0 U 0
; 5���#�►����1� '� 29,680 31,270 31,270 31,270 31,270
5����y+���" �i�t���tc��l15 ' 29,680 31,270 31,270 31,270 31,270
�r�+_�"�c� 0 0 0 0 0
�� ����.��t�S � 29,680 31,270 31,270 31,270 31,270
' `1"��������� .�_ ������'t���f5 '� 29,680 31,270 31,270 31,270 31,270 �
,.. � ���^�� ; 0 � 0 0 � � U� 0
NOTES: Developed by MWDOC as 2015 Bump Methodology
.
. . .
• s - - C•
������:'
5��� '.. ' � � �': �`1����r���l�p�Con�i'�i�n�� �
���
l��fr►e�1�w4i�h�e;�ti;' (Nari,ative�t�str�Jpiian)
p+�c�er+?t..
Applies when the City determines that due to
drought or other water supply reductions, a water
1 supply shortage exists and a consumer demand
reduction is necessary to make more efficient use
of water and appropriately respond to existing
water conditions.
Applies when the City determines that due to
drought or potable water deficiencies a water
2 supply shortage exists and a consumer demand
reduction is necessary to ensure sufficient
supplies will be available to meet anticipated
demands.
Applies when the City determines that due to
drought or potable water deficiencies a water
3 supply shortage exists and a consumer demand
reduction is necessary to ensure sufficient
supplies will be available to meet anticipated
demands.
Applies when the City adopts a resolution
declaring a water shortage emergency and
notifies its residents and businesses that a
4 significant reduction in consumer demand is
necessary to ensure sufficient supplies will be
available to meet anticipated demands.
�Qne sta�e in th�kVo�sr Shtat�v+��Cc+nting��r t�lt�n�"i�tst address a water shortage af 50%.
NOTES:
. • • � • • � • � •
s
� a ��e� � d a �� �,� .r�„
��� � 1 �.
�'f��#� ,` "' ���������t'���-
��� , DtDp d�vW�'�lst', ����tt������#p��l��+����"��`��1� ,�r���t°��`
��s�ar+�cia�only�rirt�e�vvr�e� f �c������r�� ����������
` ih��wttl be ziccep�ed by�h�::: �. . ; ' tiri�p�r�rt'��`
� UEqt�#��a►afir��ub P a�I t"" _ � x , , �, �;�
Watering or irrigating of lawn, landscape or
other
vegetated area with potable water is
prohibited between the hours of 9:00 a.m.
Landscape- Limit landscape and 5:00 p.m. Pacific Standard Time on any
Year Round day, except by use of a hand held bucket or Yes
irrigation to specific times
similar container, a hand-held hose equipped
with a positive self-closing water shutoff
nozzle or device, or for very short periods of
time for the express purpose of adjusting or
repairing an irrigation system.
Watering or irrigating of lawn, landscape or
other vegetated area with potable water
using a landscape irrigation system or a
watering device that is not continuously
attended is limited to no more than fifteen
Landscape-Other landscape �15) minutes watering per day per station.
Year Round This restriction does not apply to landscape Yes
restriction or prohibition
irrigation systems that exclusively use very
low-flow drip type irrigation systems when no
emitter produces more than two (2)gallons
water per hour, and weather based
controllers or stream rotor sprinklers_that
meet a 70%efficiency standard.
Year Round Landscape- Restrict or
prohibit runoff from Yes
Washing hard surfaces is permitted only when
necessary to alleviate safety or sanitary
hazards.This can only be performed by use of
Other- Prohibit use of
a hand-held bucket or similar container, a
Year Round potable water for washing Yes
hard surfaces hand-held hose equipped with a positive self-
closing water shut-off device or a low-volume,
high-pressure cleaning machine equipped to
recycled any water used.
Other-Customers must Fixes must be made in no more than seven (7)
Year Round repair leaks, breaks, and days of receiving notification from the City Yes
malfunctions in a timely unless other arrangements are made with the
manner City.
Water Features-Restrict Operating a water fountain or other
Year Round water use for decorative decorative water feature that does not use re- Yes
water features,such as circulated water is prohibited.
Installation of single pass cooling systems is
Year Round Other prohibited in buildings requesting new water Yes
service.
Installation of non-recirculating water systems
Year Round Other is prohibited in new commercial conveyor car Yes
was and new commercial laundry systems.
Using water to wash or clean a vehicle,
including but not limited to any automobile,
truck,van, bus, motorcycle, boat or trailer,
Other-Prohibit vehicle Whether motorized or not is prohibited,
washing except at facilities
Year Round except by use of a hand-held bucket or similar Yes
using recycled or
container or a hand-held hose equipped with
recirculating water
a positive self-closing water shut-off nozzle or
device.This subsection does not apply to any
commercial car washing facility.
Watering or irrigating of lawn, landscape or
other
vegetated area with potable water is limited
to three days per week during the months of
April through October. During the months of
November through March,watering or
irrigating of lawn, landscape or other
vegetated area with potable water is limited
to no more than two days per week.This
1 Landscape- Limit landscape provision does not apply to landscape Yes
irrigation to specific days irrigation zones that exclusively use very low
flow drip type irrigation systems when no
emitter produces more than two (2) gallons of
water per hour.This provision also does not
apply to watering or irrigating by use of a
hand-held bucket or similar container, a hand-
held hose equipped with a positive self-closing
water shut-off nozzle or device, or for very
short periods of time for the express purpose
of adjusting or repairing an irrigation system.
Other-Customers must Fixes must be made in no more than seven-
1 repair leaks, breaks,and two (72) hours of receiving notification from Yes
malfunctions in a timely the City unless other arrangements are made
manner with the City.
CII -Lodging establishment
1 must offer opt out of linen Yes
service
CII -Commercial kitchens
1 required to use pre-rinse Yes
spray valves
1 CII - Restaurants may only Yes
serve water upon request
Watering or irrigating of lawn, landscape or
other vegetated area with potable water is
limited to two days per week during the
months of April through October. During the
months of November through March,
watering or irrigating of lawn, landscape or
other vegetated area with potable water is
limited to no more than one day per week.
This provision does not apply to landscape
Landscape- Limit landscape
2 irrigation zones that exclusively use very low Yes
irrigation to specific days
flow drip type irrigation systems when no
emitter produces more than two (2)gallons of
water per hour.This provision also does not
apply to watering or irrigating by use of a
hand-held bucket or similar container,a hand-
held hose equipped with a positive self-closing
water shut-off nozzle or device, or for very
short periods of time for the express purpose
of adjusting or repairing an irrigation system.
Other-Customers must Fixes must be made in no more than forty-
Z repair leaks, breaks, and eight(48) hours of receiving notification from Yes
malfunctions in a timely the City unless other arrangements are made
manner with the City.
Filling or re-filling ornamental lakes or ponds
is prohibite, except to the extent needed to
Other water feature or sustain aquatif life, provided that such animals
Z Yes
swimming pool restriction are of significant value and have been actively
managed within the water feature prior to
declaration of a supply shortage level.
Other water feature or
Re-filling of more than one foot and initial
2 filling of residential swimming pools or Yes
swimming pool restriction
outdoor spas with potable water is prohibited.
Watering or irrigating of lawn, landscape or
other vegetated area with potable water is
limited to one day per week during the
months of April through October. During the
months of November through March,
watering or irrigating of lawn, landscape or
other vegetated area with potable water is
limited to no more than one day per week.
Landscape- Limit landscape This provision does not apply to landscape
3 irrigation zones that exclusively use very low Yes
irrigation to specific days
flow drip type irrigation systems when no
emitter produces more than two (2)gallons of
water per hour.This provision also does not
apply to watering or irrigating by use of a
hand-held bucket or similar container, a hand-
held hose equipped with a positive self-closing
water shut-off nozzle or device, or for very
short periods of time for the express purpose
of adjusting or repairing an irrigation system.
Other-Customers must Fixes must be made in no more than forty-
3 repair leaks, breaks, and eight(48) hours of receiving notification from Yes
malfunctions in a timely the City unless other arrangements are made
manner with the City.
Landscape- Prohibit all This restriction does not apply to situations to
4 ensure public health and safety or for Yes
landscape irrigation
essential govermm�et services.
No new potable water service will be
provided, no new temporary meters or
permanent meters will be provided, and no
statement of immediate ability to serve or
provide potable water service except under
the following circumstances: a valid,
unexpired building permit has been issued for
the project,the project is necessary to protect
the public's health, safety, and welfare, or the
4 Other applicant provides substantial evidence of an Yes
enforceable commitment that water demands
for the project will be offset prior to the
provision of a new water meter(s)to the
satisfaction of the City Manager or his
designess.This does not preclude the
resetting or turn-on of ineters to provide
continuation of water service or the
restoration of service that has been
interrupted for a period of one year or less.
NOTES:
. �
. . . � . . . • . . . .
f � y
�����������
�+�t��a��y,W���r�p�l�e�
Stage trro�down I'lsr ��di�iarn�l E��������c�c F�+e�i���c�
These are the��tty�t�tegories ; �t7p�'��17tX�f
t�ut�will be accepCet�by fhe :
WtJEdata online subrnitta/tool
1 Other Level 1 Water Watch Water Supply Shortage
Prohibitions
2 Other Level 2 Water Alert Water Supply Shortage
Prohibitions
3 Other Level 3 Water Warning Water Supply Shortage
Prohibitions
4 Other Level 4 Water Emergency Water Supply Shortage
Prohibitions
NOTES:
. � � � �
E 5�y
3 �G� � s����11w��. '���� � `�:����i/ � .
������������ ���� 32,119 32,119 32,119
5u�i�playr
NOTES:
. • 1 s • • • •
� Clt��W1t3'i�' �� �€��'��?ice ��a�e tif Ptil�lfi6 s ,
' Mear�ng
Anaheim p �
Santa Ana p �
Garden Grove p �
Tustin 0 �
Villa Park � �
Ct�ut��+I��rr��e �� ' I�o�ice of Public���
� ��-d,a�i��tpce �
L7rop Down 4ist �Q��jn�
Orange County p p
NOTES:
� ?
r
': �' �
Orange County Water District
Groundwater Management Plan
2015 U pdate
� * �
., -�-�.-.-.��,-�.��,�
' '�� � r
, �
t € �Jl.r r' �i,�'O,
� v�_ _m_ � � -.,�r'�.�"s,� �, PRADO
�_.r� ' F , zr�*����"�r��
,,, �� ..,, � � DAM
t=,�.
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�� �- �z�. �� � �:�`�.,��� � ��,, �.
, .�.'�"`"°'"�,,,��.��.,..,� 8A TIAGfl �i' f����,�� � # '���' �.
ftEEK '
aw�s +r.�a w��R ..�� �.�.��� ; r. e',..��►`�
� PURI�i�l4 FICCILItY ``-.� � � '� ��`�>°' ' , ,
�.. � �.� �� ��� �;��'�:��
�`� �,,, ��.� �,�-,�. :�� � �p���
°� � ;"�;� � °- -�,� � . �
SEAWATER �� �� �'°� ��r,;� °��°3��/� ,g��r{'.;i l
INTRUSION � �. ��,
FACtL`� ��
BARRIER � �,�
, `-��� °,,� .,,,,�� �� r'
OCSD TREATMENT e'� � � '�, '`�'°� � � �
FACILITY �� � � �°�,,.,� � � '�: �;,, ' ' �'{8 ti � @ � s . t �.
� � � �� <
OCEAN � ,.-��'� � °� �, �� C Q�tt t y. ��
OUTFLOW ` :�
�� ��.,� ,� T �:
PACIFtC �'"� , "��"• �� ��`~�,, �� � �
OCEAN ',',r;�.r`��t� �w' "°�... 'r
�.3 ���i°: .�'�� ��'r`,'; , "'�,, -;,
�;�Iw�1�� � "'�` � �;i' �
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�µ �
,.'!�i',`
*
Orange County Water District
Graundwater Management Plan
2015 Update
June 17, 2015
Greg Woodside, PG CHg, Executive Directo� of Pianning and Natural Resources
Marsha Westropp, Senior Watershed Pianner
The primary authors of the Groundwater Management Plan wish to acknowledge
Steve Strand who prepared the majority of maps and assisted with data
management.
Thanks also for the significant contributions of the following District staff in
preparing the Plan: Nira Yamachika, Adam Hutchinson, Roy Herndon, John
Kennedy, Tim Sovich, Gary Yoshiba, David Field, Jason Dadakis, Karen Underhill,
Bill Dunivin, Li Li, Linda Koki, John Bonsangue, Diane Pinnick, Dick Zembal, Darla
Cirillo, Leticia Villarreal, Rae Krause, Nic Nguyen, Don Brown, Lynn McConnell, and
Renee Patterson. ,
Graphic art and design assistance provided by Scott Brown Graphics.
Table of Contents
Section Paqe
EXECUTIVE SUMMARY..............................................................................
E 1
SECTION 1 HISTORYAND GOVERNANCE...........................................................1-1
1.1 Introduction......................................................................................................1-1
1.2 History of the Orange County Water District....................................................1-2
1.3 OCWD Governance.........................................................................................1-5
1.4 Groundwater Producers...................................................................................1-9
1.5 Public Education and Events.........................................................................1-10
SECTION 2 PREPARATION OF GROUNDWATER MANAGEMENT PLAN ...........2-1
2.1 Introduction......................................................................................................2-1
2.2 Sustainable Groundwater Management Act....................................................2-2
2.3 Basin Management Goals and Objectives.......................................................2-3
2.4 Recommendations and Projects Completed 2009-2015.................................2-7
2.5 Recommendations for 2015-2020 .................................................................2-10
2.6 Planning and Implementation Horizons.........................................................2-11
SECTION 3 BASIN HYDROGEOLOGY ...................................................................3-1
3.1 Description of Basin Hydrogeology..................................................................3-1
3.2 Determination of Total Basin Volume ..............................................................3-6
3.3 Water Budget...................................................................................................3-8
3.4 Calculation of Change in Groundwater Storage............................................3-13
3.5 Elevation Trends............................................................................................3-17
3.6 Land Subsidence...........................................................................................3-22
3.7 Basin Model...................................................................................................3-25
SECTION 4 WATER SUPPLY MONITORING..........................................................4-1
4.1 Introduction......................................................................................................4-1
4.2 Groundwater Monitoring ..................................................................................4-1
4.3 Recycled Water Monitoring............................................................................4-10
4.4 Surface Water Monitoring..............................................................................4-11
4.5 Water Resources Management System: Database Management.................4-17
4.6 Water Sample Collection and Analysis..........................................................4-18
4.7 Ground and Surface Water Interactions ........................................................4-21
SECTION 5 MANAGEMENT AND OPERATION OF RECHARGE FACILITIES......5-1
5.1 History of Recharge Operations ......................................................................5-1
QCWD Grc��andw�ter Managerr�er�t Plan 2015 Update ii
Table of Contents
5.2 Sources of Recharge Water Supplies..............................................................5-3
5.3 Surface Water Recharge Facilities................................................................5-12
5.4 Maintenance of Recharge Facilities...............................................................5-17
5.5 Recharge Studies and Evaluations................................................................5-18
5.6 Improvements to Recharge Facilities 2009-2014..........................................5-25
SECTION 6 GROUNDWATER REPLENISHMENT SYSTEM..................................6-1
6.1 Overview..........................................................................................................6-1
6.2 Advanced Water Treatment Process...............................................................6-5
6.3 Energy Efficient Operations...........................................................................6-76
6.4 Plant Optimization and Expansion...................................................................6-7
6.5 Water Quality Monitoring and Reporting..........................................................6-9
6.6 Public Outreach .............................................................................................6-10
SECTION 7 SEAWATER INTRUSION AND BARRIER MANAGEMENT.................7-1
7.1 Background......................................................................................................7-1
7.2 Talbert Seawater Intrusion Barrier...................................................................7-2
7.3 Alamitos Seawater Intrusion Barrier..............................................................7-66
7.4 Sunset Gap Investigation...............................................................................7-88
7.5 Evaluation of Potential Impacts Due to Climate Change...............................7-99
SECTION 8 WATER QUALITY PROTECTION AND MANAGEMENT.....................8-1
8.1 OCWD Groundwater Quality Protection Policy................................................8-1
8.2 Well Development, Management and Closure................................................8-2
8.3 Managing Salinity in Water Supplies...............................................................8-3
8.4 Management of Nitrates in Groundwater.......................................................8-10
8.5 OCWD Prado Wetlands.................................................................................8-12
8.6 Amber-Colored Groundwater Management...................................................8-15
8.7 Regulation and Management of Contaminants .............................................8-16
8.8 Constituents of Emerging Concern................................................................8-20
8.9 Groundwater Quality Improvement Projects..................................................8-22
8.10 BEA Exemption for Improvement Projects ....................................................8-26
SECTION 9 NATURAL RESOURCE AND COLLABORATIVE WATERSHED
PROGRAMS ..............................................................................................................9-1
9.1 OCWD Natural Resource Programs— Overview............................................9-1
9.2 Natural Resource Programs in the Watershed................................................9-2
OCWd Grcaundwater Management Plan 2015 Update iii
Table of Contents
9.3 Collaborative Watershed Programs...............................................................9-10
9.4 Management of Areas Within Basin 8-1 Outside OCWD Boundaries..........9-15
9.5 Orange County Water Resources-Related Plans..........................................9-16
9.6 Collaboration with Federal and State Agencies.............................................9-18
9.7 Land Use, Development and Environmental Reviews...................................9-21
SECTION 10 SUSTAINABLE BASIN MANAGEMENT.............................................10-1
10.1 Background...................................................................................................10-1
10.2 Basin Operating Range ................................................................................10-2
10.3 Balancing Production and Recharge ............................................................10-5
10.4 Managing Basin Pumping.............................................................................10-6
10.5 Supply Management Strategies...................................................................10-10
10.6 Removing Impediments to Conjunctive Use................................................10-11
10.7 Water Demands...........................................................................................10-12
10.8 Drought Management..................................................................................10-15
10.9 Record Keeping...........................................................................................10-16
SECTION 11 FINANCIAL MANAGEMENT...............................................................11-1
11.1 Background Financial Information .................................................................11-1
11.2 Operating Expenses......................................................................................11-1
11.3 Operating Revenues......................................................................................11-2
11.4 Reserves...........................................:............................................................11-3
SECTION 12 REFERENCES AND ACRONYMS .....................................................12-1
t7�CWD Grourtdwater Management Pian 2015 Update iv
Table of Contents
Table Paqe
Table 1-1: Major Groundwater Producers within OCWD Boundaries........................1-9
Table 2-1: Basin Management Objective: Groundwater Quality ..............................2-3
Table 2-2: Basin Management Objective: Basin Sustainable Yield ..........................2-5
Table 2-3: Basin Management Objective: Operational Efficiency ............................2-6
Table 2-4: 2009 Recommendations: Completed............................................................2-7
Table 2-5: 2009 Recommendations: On-going ..............................................................2-8
Table 2-6: Completed Projects/Accomplishments 2009-2015 .......................................2-9
Table 2-7: Recommendations for 2015-2020...............................................................2-10
Table 3-1: Estimated Basin Groundwater Storage by Hydrogeologic Unit ....................3-8
Table 3-2: Example Annual Basin Water Budget...........................................................3-9
Table 4-1: Monitoring of Regulated and Unregulated Chemicals ..................................4-6
Table 4-2: Groundwater Replenishment System Product Water Quality Monitoring ...4-10
Table 4-3: Surface Water Quality Sampling Frequency within Orange County...........4-14
Table 4-4: OCWD Publications....................................................................................4-21
Table 5-1: Sources of Recharge Water Supplies...........................................................5-3
Table 5-2: Annual Recharge by Source.........................................................................5-4
Table 5-3: Area and Storage Capacities of Surface Water Recharge Facilities ..........5-12
Table 5-4: Estimated Future Santa Ana River Storm Flow Arriving at Prado Dam......5-23
Table 5-5: Santa Ana River Flow Conditions and Estimated Average Inflow to Prado
Dam............................................................................................................5-23
Table 5-6: Annual Yield of Potential Surface Water Recharge System Projects.........5-24
Table 8-1: Secondary Drinking Water Standards for Selected Constituents .................8-4
Table 8-2: TDS Water Quality Objectives for Lower Santa Ana River Basin Management
Zones ...........................................................................................................8-5
Table 8-3: Salt Inflows for Orange County and Irvine Management Zones ...................8-7
Table 8-4: Nitrate-nitrogen Water Quality Objective for Lower Santa Ana River
Basin Management Zones .............................................................8-11
Table 8-5: Summary of BEA Exemption Projects ........................................................8-26
Table 10-1: Benefits and Constraints of Changing Storage Levels .............................10-3
Table 10-2: Groundwater Production and Recharge Sources ....................................10-5
Table 10-3: Management Actions based on Change in Groundwater Storage............10-9
Table 10-4: Conjunctive Use Impediments and Opportunities...................................10-11
Table 10-5: Estimated Future Water Demands in OCWD Service Area....................10-13
Table 10-6: Projected Total Water Demands.............................................................10-13
Table 10-7: Projected Population within OCWD Boundaries.....................................10-14
Table 10-8: Approaches to Refilling the Basin...........................................................10-16
Table 11-1: FY 2014-15 Budget Operating Expenses .................................................11-1
Table 11-2: FY 2014-15 Operating Revenues.............................................................11-2
OCW� Groundwater Management Plan 2015 Update y
Table of Contents
Fiaure Paae
FigureES-1: Burris Basin........................................................................................... ES1
Figure ES-2: DWR Basin 8-1 and OCWD Boundary ................................................. ES2
Figure ES-3: OCWD Wells and Title 22 Drinking Water Wells .................................. ES3
Figure ES-4: Sources of Groundwater Recharge ...................................................... ES4
Figure ES-5: GWRS Facilities.................................................................................... ES5
Figure ES-6: Mesas and Gaps Along the Orange County Coast............................... ES6
Figure ES-7: OCWD Prado Wetlands........................................................................ ES7
Figure ES-8: Least Bell's Vireo.................................................................................. ES8
Figure ES-9: Groundwater Production....................................................................... ES9
Figure ES-10: Groundwater Storage.......................................................................... ES10
Figure ES-11: Impacts of Change in Groundwater Storage Levels........................... ES11
Figure 1-1: OCWD Board of Directors, circa 1935.........................................................1-1
Figure 1-2: District Boundary, 1933 ...............................................................................1-2
Figure 1-3: Anaheim Lake, circa 1961 ..........................................................................1-3
Figure 1-4: Water Factory 21, circa 1975.......................................................................1-4
Figure 1-5: GWRS Reverse Osmosis Building .............................................................1-5
Figure 1-6: Board of Directors Service Area ..................................................................1-6
Figure 1-7: OCWD Board of Directors Meeting in Fountain Valley................................1-7
Figure 1-8: Retail Water Agencies within OCWD.........................................................1-10
Figure 1-9: Group Attending the 2015 Children's Water Education Festival................1-11
Figure 1-10: 2014 Orange County Water Summit........................................................1-12
Figure 1-11:2014 GroundwaterAdventure Tour.........................................................1-13
Figure 1-12: OCWD Public Tour..................................................................................1-14
Figure 2-1: Meeting of OCWD Staff with Groundwater Producers.................................2-1
Figure 3-1: Coastal Plain of Orange County Groundwater Basin, Basin 8-1 .................3-1
Figure 3-2: Geologic Cross-Section, Orange County Groundwater Basin.....................3-3
Figure 3-3: Orange County Groundwater Basin.............................................................3-4
Figure 3-4: Basin 8-1 and OCWD Boundaries...............................................................3-7
Figure 3-5: Estimated Subsurface Recharge...............................................................3-10
Figure 3-6: Distribution of Groundwater Production, Water Year 2013-14 ..................3-11
Figure 3-7: Relationship between OCWD Basin Storage and .....................................3-12
Figure 3-8: Schematic Cross-Section of the Basin Showing Three Aquifer Layers....3-14
Figure 3-9: Groundwater Level Contour Map, June 2014............................................3-15
Figure 3-10: Groundwater Level Changes, June 2013-14...........................................3-16
Figure 3-11: Change in Groundwater Storage, WY 1974-75 to 2013-14.....................3-17
Figure 3-12: Principal Aquifer Groundwater Elevation Profiles, 1969 and 2013..........3-18
Figure 3-13: Location of Long-Term Groundwater Elevation Hydrograph ...................3-18
Figure 3-14: Water Level Hydrographs of Wells SA-21 and GG-16 in Pressure Area.3-19
Figure 3-15: Water Level Hydrographs of Well A-27 in Forebay .................................3-20
Figure 3-16: Water Level Hydrographs of Wells SAR-1 and OCWD-CTG1 ................3-21
Figure 3-17: Orange County Public Works GPS Real Time Network..........................3-23
Figure 3-18: Available Storage Space and Ground Surface Elevation Change..........3-24
Figure 3-19: Basin Model Extent..................................................................................3-25
Figure 3-20: Model Development Flowchart................................................................3-28
OCWD Groundwater Managemer�t Pian 2015 Update vi
Table of Contents
Figure 3-21: Basin Model Calibration Wells.................................................................3-30
Figure 3-22: Calibration Hydrograph of Monitoring Well AM-5A..................................3-31
Figure 3-23: Calibration Hydrograph for Monitoring Well SC-2....................................3-32
Figure 3-24: Calibration Hydrograph for Monitoring Well GGM-1 ................................3-32
Figure 3-25: Talbert Gap Model and Basin Model Boundaries....................................3-35
Figure 3-26: Talbert Model Calibration Wells and Boundary Wells..............................3-36
Figure 3-27: Talbert Gap Model Aquifer Layering Schematic......................................3-36
Figure 4-1: OCWD-Owned Monitoring Wells.................................................................4-2
Figure 4-2: Large and Small System Drinking Water Wells...........................................4-2
Figure 4-3: Private Domestic, Irrigation, and Industrial Wells in ....................................4-4
Figure 4-4: Wells in CASGEM Program.........................................................................4-5
Figure 4-5: OCWD Staff Collecting Water Sample at Production Well ..........................4-7
Figure 4-6: North Basin Groundwater Protection Program Monitoring Wells................4-8
Figure 4-7: South Basin Groundwater Protection Program Monitoring Wells...............4-8
Figure 4-8: Seawater Intrusion Monitoring Wells..........................................................4-9
Figure 4-9: GWRS Monitoring Wells...........................................................................4-11
Figure 4-10: Surface Water Monitoring Locations .......................................................4-13
Figure 4-11: Basin Monitoring Program Task Force Monitoring Locations..................4-15
Figure 4-12: OCWD Advanced Water Quality Assurance Laboratory .........................4-19
Figure 4-13: Monitoring Well Designs..........................................................................4-20
Figure 4-14: Westbay Well Schematic.........................................................................4-20
Figure 4-15: Santa Ana River in Orange County,1938 ................................................4-22
Figure 5-1: Santa Ana River, view upstream .................................................................5-1
Figure 5-2: Anaheim Lake and Mini Anaheim Lake.......................................................5-2
Figure 5-3: Five Year Average Recharge by Source.....................................................5-4
Figure 5-4: Santa Ana River Watershed ........................................................................5-5
Figure 5-5: Area of Inundation and Storage Volume for Water Conservation Pools......5-6
Figure 5-6: Annual Base and Storm Flow in the Santa Ana River at Prado Dam..........5-7
Figure 5-7: Precipitation at San Bernardino, Water Year (Oct.-Sept.) ..........................5-8
Figure 5-8: Historical Recharge in SurFace Water Recharge System............................5-8
Figure 5-9: Santiago Basins and Santiago Creek..........................................................5-9
Figure 5-10: Net Incidental Recharge and Precipitation, WY 2000-01 to 2013-14 .....5-10
Figure 5-11: OCWD Surface Water Recharge Facilities.............................................5-13
Figure 5-12: Recharge Basin showing Accumulated Clogging Layer.........................5-17
Figure 5-13: Bulldozer in Off-River Channel Removing Clogging Layer......................5-18
Figure 5-14: Recharge Facilities Model System Overview...........................................5-20
Figure5-15: Miraloma Basin........................................................................................5-26
Figure 5-16: Santiago Basins Pump Station ................................................................5-27
Figure 5-17: Sand and Cobble Sediments in Santa Ana River Channel......................5-28
Figure 6-1: Aerial View of the Groundwater Replenishment System.............................6-2
Figure 6-2: Groundwater Replenishment System Facilities...........................................6-3
Figure 6-3: Water Factory 21, circa 1975.......................................................................6-4
Figure 6-4: AWPF Process Flow Diagram .....................................................................6-5
Figure 6-5: Flow Equalization Tanks..............................................................................6-8
Figure 6-6: Group Touring the Groundwater Replenishment System..........................6-10
Figure 7-1: Coastal Gaps in Orange County..................................................................7-1
OCW�7 Ground�ater Management Plan 2015 Update vii
Tabie of Contents
Figure 7-2: Talbert Barrier Injection Wells......................................................................7-3
Figure 7-3: Talbert Gap 250 mg/L Chloride Concentration Contours ............................7-4
Figure 7-4: Groundwater Elevations and Chloride Concentrations at OCWD-M27 .......7-5
Figure 7-5: Groundwater Elevations and Chloride Concentrations at HBM-2/MP1 .......7-5
Figure 7-6: Alamitos Gap Injection and Monitoring Wells..............................................7-7
Figure 7-7: Sunset Gap Monitoring and Production Wells.............................................7-9
Figure 8-1: Groundwater Management Zones in Orange County..................................8-4
Figure 8-2: TDS in Groundwater Production Wells........................................................8-6
Figure 8-3: Total Flow Weighted Average TDS of All Source Waters............................8-8
Figure 8-4: Tons of Salt in GWRS vs. Imported Water..................................................8-9
Figure 8-5: Areas with Elevated Nitrate Levels............................................................8-11
Figure 8-6: Location of Prado Wetlands.......................................................................8-12
Figure 8-7: Aerial View of Prado Wetlands..................................................................8-13
Figure 8-8: Wetlands Pond Schematic.........................................................................8-14
Figure 8-9: Extent of Amber-Colored Water.................................................................8-15
Figure 8-10: Groundwater Cleanup Projects................................................................8-17
Figure 8-11: Sample Analysis at OCWD Laboratory....................................................8-18
Figure 8-12: Water Quality Improvement Projects.......................................................8-22
Figure 8-13: North Basin Groundwater Contamination Plume.....................................8-23
Figure 8-14: South Basin Groundwater Contamination Plume ....................................8-24
Figure 9-1: View of Prado Basin Looking East with Prado Dam in Foreground.............9-2
Figure 9-2: Prado Mitigation Areas ................................................................................9-3
Figure 9-3: Least Bell's Vireo.........................................................................................9-4
Figure 9-4: Least Bell's Vireo Survey Data 1983...........................................................9-5
Figure 9-5: Least Bell's Vireo Survey Data 2014 ...........................................................9-5
Figure9-6: Arundo........................................................................................................9-6
Figure 9-7: Santa Ana Sucker........................................................................................9-7
Figure 9-8: Gabion in Santa Ana River..........................................................................9-8
Figure 9-9: Bird Habitat Island Constructed in Burris Basin...........................................9-9
Figure 9-10: Tree Swallows Nesting, Lower Santa Ana River, 2014 ...........................9-10
Figure 9-11: Tree Swallow Nest Box............................................................................9-10
Figure 9-12: WACO Meeting in Fountain Valley..........................................................9-14
Figure 9-13: Areas Outside OCWD Boundaries ..........................................................9-15
Figure 9-14: OCWD Recharge Operations Staff..........................................................9-18
Figure 9-15: Aerial View of Orange County .................................................................9-21
Figure 10-1: Schematic Illustration of Impacts of Changing the Amount of Groundwater
inStorage..................................................................................................10-4
Figure 10-2: Basin Production and Recharge Sources, WY 1999-00 to 2013-14........10-5
Figure 10-3: Assigned and Actual Basin Production Percentage ................................10-7
Figure 10-4: BPP Calculation.......................................................................................10-8
Figure 10-5: Areas Supplied by GAP Water ..............................................................10-11
Figure 10-6: Historic Total District Water Demands...................................................10-12
C7CWD Grc�undwat�r Managemer�t Plan 2015 Upda#e viii
Table of Contents
APPENDICES
Appendix A Public Notices
Appendix B Groundwater Management Plan Mandatory and Recommended
Components and Sustainable Groundwater Management Act Required
and Additional Plan Elements
Appendix C Basin Management Objectives: Achievement of Sustainability for Long-
Term Beneficial Uses of Groundwater
Appendix D Report on Evaluation of Orange County Groundwater Basin Storage and
Operational Strategy
Appendix E List of Wells in OCWD Monitoring Programs
Appendix F Monthly Water Resources Report
C1CW� Groundwater Managemer�t Plan 2015 Update ix
Executive Summary
EXECUTIVE SUMMARY
The Orange County Water District (OCWD; the District) is a special district formed to
manage the Orange County Groundwater Basin. Water from the basin provides
approximately 70 percent of the water supply for residents in north and central Orange
County.
INTRODUCTION
OCWD was created in 1933 by the California legislature to manage the Orange County
Groundwater Basin. The District operates the basin in order to protect and increase the
basin's sustainable yield in a cost-effective manner. Water produced from the basin is the
primary water supply for approximately 2.4 million residents living within the District
boundaries.
OCWD manages the groundwater basin and seeks to expand the basin's annual yield by
maximizing the amount of water recharged into the basin, developing new sources of water to
recharge the basin, and increasing the effectiveness of the DistricYs facilities. OCWD is
governed by a 10-member Board of Directors. Cities, water agencies and other groundwater
producers meet on a monthly basis with District staff to provide input and advice on basin
management issues.
Water demands have grown substantially since the DistricYs founding. This has challenged
OCWD to increase groundwater recharge, establish methods to effectively manage demands
on the basin, and balance the amount of total recharge and total pumping to maintain water
levels and storage within the established safe operating range.
,.; �.,�
�'`'� • s
. : :
- , . .
OCWD Groundonr�ter Management Plan 2015 lJpdat� ES9
Executive Summary
The District's first Groundwater Management Plan was published in 1989; the Groundwater
Management Plan 2015 Update is the fifth update. In 2014, the California Sustainable
Groundwater Management Act was passed. The new law provides authority for agencies to
develop and implement Groundwater Sustainability Plans or alternative plans that
demonstrate the basin has operated within its sustainable yield over a period of at least 10
years. Elements to be included in sustainability plans as described in the California Water
Code (§10727.2, 10727.4, and 10727.6) have been incorporated into this plan.
Groundwater basin management goals are (1)to protect and enhance groundwater quality,
(2)to protect and increase the sustainable yield of the basin in a cost-effective manner, and
(3)to increase the efficiency of District operations.
BASIN HYDROGEOLOGY
The Orange County Groundwater Basin is located within an area designated by the California
Department of Water Resources as Basin 8-1. The boundaries of the "Coastal Plain of Orange
County Groundwater Basin" and OCWD boundaries are shown in Figure ES-2. The basin
stores an estimated 66 million acre-feet of water, although only a fraction of this can be
sustainably pumped without causing physical damage such as seawater intrusion or potential
land subsidence. Annual changes in the amount of groundwater stored in the basin are
estimated using groundwater elevation measurements and aquifer storage coe�cients for the
three primary aquifer systems in the
�"�� �":��� ��t`����� ��� ,�� � basin. These estimated storage
... _.
��,� � � �`� ���. .
� P������� � r�� ������ changes are backed up with
LOS AN6ELE5 �� '*r'#+�. ��''BERNARDINO,;„ .....
��Hr ..,.,...�..t � �,��; " � comprehensive measurements of
�_„ ;��� �`
� ,���� � .. �-��� ��:'�����Y� groundwater production and managed
� � , , recharge so that a fairly precise
`,� # �r����� �� �x�� estimate of groundwater stora ge is
� ��� �;� t �, known on a monthly basis.
a ,�� �,�^' � �,
�
�� �, ��' � ��; OCWD's groundwater basin model
a_1 ' � ""� .
,, ;� �` was developed to evaluate basin
� roduction ca acit and rechar e
� ,��'��� ' �� P P Y 9
' � ' � �� requirements and has improved the
fi�.
��� `"��� � district's overall understanding of
couHTv ,� � ,�-
� ����` ��s
groundwater flow dynamics. Typical
9�,,�, applications of the basin model
�'���� include estimating annual change in
h �' :�.,�-"� � � � groundwater storage and the effects
w'� -' � of potential future pumping and
a ., �� C7a'^Ac�«�^�:�*��3��"���^„d� rechar e ro'ects on groundwater
o s ,a`� 4 �';ocvyuaa,�aen
9 P 1
�.`..�`"`� �_t ��y���� levels, storage, and the water budget.
Figure ES-2: DWR Basin 8-1 and OCWD Boundary
OCWC} �raundwater M�n�gement Plan 2015 Update ES2
Executive Summary
WATER SUPPLY MONITORING
OCWD collects water elevation and water quality data from nearly 700 wells, including over
400 District-owned monitoring wells, shown in Figure ES-3. Comprehensive water quality
monitoring programs are conducted to comply with permits and drinking water regulations, to
conduct research programs, and to manage the groundwater basin. The District operates its
own laboratory that is state-certified to perform bacteriological, inorganic, and organic
analyses.
All entities that operate large-capacity wells must equip their wells with meters and report their
production totals every six months. Approximately 200 large-capacity municipal and privately-
owned supply wells account for 97 percent of production. At the District's request, for the
purposes of more precise and current knowledge of basin conditions and model calibration,
owners of large-capacity wells have reported monthly production for each of their wells since
1988. All production and � ��
monitoring wells are measured � r•, " '����'�"�:_ ��� ���'��� ��.���.
�` �� � � f
for groundwater elevation at ��� , ` �= ~-�" �� �� �
�
least every six months. �•a �� �°��''�� � �������, ���
�a� �' � ��1��' � �,��,���>
'� ,� 4 1
Water quality samplin9 ;� � ��,, � �� �,�� "- , ,��"�� - � ��'��' ���
� � ��� �
programs vary year-to-year ; �'; � 4$ � � �`��� ���"�� � �� � `
✓kr eG& y .�, � .� S
��: � w���
�„
b8S@CI O� P2gUI8tOI')/ ���' �' � � d � � y �� y � � �� . ��
requirements and basin �� � �� � '"� �,�� �� � � � ��� � ����° ,-�` �
conditions. In 2014, OCWD � � '�¢ � '�'�� • ,�s � ,�' �' ��" �
� � a� � �� . � � � ,� `� �
water quality staff collected � � �F ,
�`"�. �' � � a � � � �': � � ,. �,
17,046 sam les, 4,142 of which ,��� � `�' ��� � �'"'� � �" ' °�� ��°
p �� � "� �` `��`�" e�'� • �.r�' ,�.� ��
were collected from drinking ��f ��� � ��� � ���"�� �� � .,,. ,� � ����>'
�� .�� �° ,..
water wells. OCWD conducts ���,� ,� ����3�°��:�_� � � ±, .`_.�; ������':o
.
Title 22 drinking water quality `.. �"f4 � �� �� �, �� �� � �� � ������ ��. �'
monitorin on behalf of the �' � �' � � � � ` ' �%� �'� ��
g '''+,. `"� s�^' �, ° re�� '+ �r„�x�'
Groundwater Producers. 4' ,, � �
� �' ,�,� ` .-�.�: �' ��,�'',� � `*F k ��3���
Additional groundwater ���� � � ����'��=°�
� .'C.� E � � � '���,< � -� s OCWOMontorigNbq �+
programs include monitoring of • ,� . ��M w�M����,�
i � ��^*.� � t �'fr AclNe Larqe-System DrIMt1Ap Nqter Welt �
groundwater contamination 0 46,OOD 20,960 �� b pclweSm8145ystemDrinknpVWtxWeM
plumes, recycled recharge ��°°' � �� ���°�"'°�°""°°" �3
water quality and extent of Figure ES-3: OCWD-Owned Wells and �Wells in ��
seawater intrusion. Title 22 Drinking Water Monitoring Program
OCWD monitors surface water used for groundwater recharge including Santa Ana River
water and imported water as well as recycled water produced by the District's Groundwater
Replenishment System. Flows in and out of the District's Prado Wetlands are monitored to
evaluate changes in water quality and to evaluate the efFectiveness of the treatment wetlands.
Data collected by OCWD are stored in the District's electronic database and geographic
information system, known as the Water Resources Management System. The database
O�V�D Grc�undwater I�Canagemen� Plan 2015 Update ES3
Executive Summary
contains comprehensive well information, current and historical data, and information on sub-
surface geology and groundwater modeling.
MANAGEMENT AND OPERATION OF RECHARGE FACILITIES
Replenishing the groundwater basin is essential to support pumping from the basin. Although
the amount of recharge and basin pumping may not be the same each year, over the long-
term recharge needs to approximately equal total pumping, as it has for decades. Recharge
water supplies and their respective proportion of total recharge supplies are shown in Figure
ES-4.
The District's surface water recharge system is comprised of 23 recharge facilities with a
combined maximum storage capacity of approximately 26,000 acre-feet. Recharge basins
are located adjacent to the Santa Ana River in the City of Anaheim and Santiago Creek in the
City of Orange.
o Santa Ana River Base Flow ■Storm Flow �e Imported Water
■Recycled Water �In-Lieu Program �Incidental Recharge
��.�..�.�
In-Lieu Program
-•
• .
.,� -�
Figure ES-4 Sources of Groundwater Recharge
Average for Water Years 2009-10 to 2013-14
OCWD Graundwater IVlan�gerner�t Plan 2015 Update ES4
Executive Summary
GROUNDWATER REPLENISHMENT SYSTEM
The Groundwater Replenishment System (GWRS) is OCWD's recycled water purification
system in operation since 2008 (Figure ES-5). The plant was jointly constructed by OCWD
and the Orange County
g ���° �°'� �'`[''� Sanitation District. Wastewater
���. ,. g s ,-..��Sa� �`
MIIMIAGED °,'� � �....-,,,, ' �;:,f�a�v°�`��-
aY�a , � ,; �,��r�,� � that would otherwise be
�,�SXMt'Cl� � ��
, �� discharged to the Pacific Ocean
'°a, �� � �'����� � ;��;� ��_ is purified using a three-step
,
, ���������'.� � � ��` ,�� � ��;; � process (microfiltration, reverse
� �� � ` �� � °�`�� � 'r' ���� osmosis and advanced
,� � � � .� ,
� ,���;`;��.� ��. � <
�� �'� � � $ �. �� ° � ��, � 3�� ��` oxidation/disinfection) to
� � �,� � � � � °��� �� produce high-quality water used
��� � ��� ��� .� �,.�-���
�-�� � � � � � � � >e ��< � `��* : to recharge the groundwater
�°°� ��.�.��-��`� � ��t�'�,�ai� �� r_ � �r
��ti� 2��Y2 �r� E�►�� �. � ����° �d� basin and for in ection into the
�� � � � � � . J
� � � ��� ��.�� ` " x�` �°�,"�����;�, Talbert Seawater Intrusion
� '°°�� '� �t ` ��� "'��s��� �r��r��,' Barrier. When first completed,
' ���`� ` � ";,; � ;� �a_ the plant produced up to 70
SEAWATER �� � � �` �`�� �`�t
�NTeus�oN '°� � � �� °� �� � ��� million gallons per day or
BARRIER �'�"��' �� '�
, �, � approximately 72,000 acre-feet
ocso rRearMer,r ��� �� �� ��"`��;� �� � per year(afy) of product water.
FAc���ry >�� � ��°"�� �- Q:��a n g e Initial expansion of the plant
,'� �,
ocEaH -�. �� , ��" . � ��° G o�n t y was completed in 2015
ourF�ow h
�.—�-�,� . �� ,r `,,
`�� 's� �,� a� ` � � � � increasing production up to
PACIFIC � ,,t'��' y
ocEAN '``�;f���.���� �`w �� � � � 100,000 afy of recycled water.
�."a r �� .��s � � °^ -'i
Figure ES-5: GWRS Facilities
SEAWATER INTRUSION MONITORING AND BARRIER MANAGEMENT
Monitoring and preventing the encroachment of seawater into fresh groundwater zones along
the coast is a major component of OCWD's sustainable basin management. Seawater
intrusion became a critical problem in the 1950s. Overdraft of the basin caused water levels
to drop as much as 40 feet below sea level; seawater intruded three miles inland. Risk of
seawater intrusion is greatest in coastal lowland areas, or gaps, between relatively flat
elevated areas referred to as mesas as shown in Figure ES-6.
The Alamitos Seawater Intrusion Barrier was constructed in 1965 to protect the Central Basin
of Los Angeles County and the Orange County Groundwater Basin from seawater intrusion
through the Alamitos Gap. The barrier facilities are jointly owned by the Los Angeles County
Flood Control District and OCWD and include 43 injection wells and 177 active monitoring well
sites.
OCWD constructed the Talbert Seawater Barrier in 1975 with 23 injection well sites to halt
seawater intrusion through the Talbert Gap, a 2.5 mile geological feature befinreen the
OCWD Grour►dwater IVlar�agement Plan 2015 Upd�t� ES5
Executive Summary
Newport and Huntington Mesas. Today, the Talbert Barrier is composed of a series of 36 well
sites that are used to inject an average of 36,000 afy of water into four aquifer zones. This
forms a hydraulic barrier to seawater that would otherwise migrate inland toward areas of
groundwater production.
�, < � �r
Basin monitoring for
�� �� s � � � � � � + potential seawater
� • '�
'�A�aM�Tos s� �, intrusion in the vicinity of
�' '` ' eaRR�E� a� " ��``��—#--�� � �' the Sunset Gap began in
� . �
Alamitos ,� the 1950s. In 2007, a well
����� ��� �tt � � ����' � � �� � „�� � in the City of Huntington
� � � � � ` Beach was permanently
U �
SQap t �, � �, 6 �� " � removed from service due
� ,,��,��� � � $ � � '� � y�, � �,� to high salinity levels.
, ��� � � � � � � Studies commenced and
� � � �� � " monitoring wells were
ed� � ��N���� ��� � �� � �
� ,p ���� �� � � � � constructed. Strategies to
� �;''TA�sEar eaR��ER�� control intrusion bein
�, � �e � �� 9
' �� � � � � considered include design
�
� �� �' r��� ��� �� of a potential future
��,r a�bert�� � southerly extension of the
°��� G�P� `� Alamitos Barrier.
� � � Additional remedial
� measures beyond source
" �=���` � control may be
yr ���-- � R Active Large-System Produclion Wtrll.
, ,��,�,�u considered, such as
S 3� MoNtonngN/efl brackish groundwater
0 5.000 10.000 ♦ Multiport Monitotitg Well
�F�� � PathwayINSeawaterintrusion extraction and
desalination.
ES-6: Mesas and Gaps Along the Orange County Coast
WATER QUALITY PROTECTION
OCWD adopted the first Groundwater Quality Protection Policy in 1987; the latest revision
was adopted by the Board of Directors in 2014. The policy guides the actions of OCWD to
prevent groundwater quality degradation, undertake investigation and clean up as necessary
to protect the basin from contamination, and encourage appropriate treatment of poor-quality
groundwater.
OCWD Graundwater M�nagement Plan 2015 U�d�te ES6
Executive Summary
Salinity Management
Since Santa Ana River water is a major source of recharge for the basin, salt management
programs in the upper watershed are vital to protect the water quality in Orange County. A
watershed-wide salinity management program is implemented by watershed stakeholders
under the direction of the Santa Ana
Regional Water Quality Control Board.
In addition, recharging the Orange County
Groundwater Basin with recycled water
produced by the GWRS is expected to
reduce salinity levels over the long-term.
To reduce the level of nitrate in Santa Ana
River water, OCWD operates an extensive
system of wetlands in the Prado Basin,
shown in Figure ES-7. OCWD diverts
approximately half of the non-storm flows of
the Santa Ana River through the wetland
ponds that remove approximately 15 to 40
tons of nitrates a month, depending on the
season. Figure ES-7: OCWD Prado Wetlands
Groundwater Contamination
OCWD efforts to protect the groundwater basin and to assess the potential threat to public
health and the environment from contamination in the Santa Ana River watershed and within
Orange County include:
• Reviewing on-going groundwater cleanup site investigations and commenting on the
findings, conclusions, and technical merits of progress reports;
• Providing knowledge and expertise to assess contaminated sites and evaluating the
merits of proposed remedial activities; and
• Conducting third-party groundwater split samples at contaminated sites to assist
regulatory agencies in evaluating progress of groundwater cleanup.
OCWD lacks the regulatory authority to require responsible parties or potentially responsible
parties to clean up pollutants that have contaminated groundwater. In some cases, the District
has pursued legal action against entities that have contaminated the groundwater basin to
recover the District's remediation costs. In other cases, the District coordinates and
cooperates with regulatory oversight agencies that investigate sources of contamination.
The District also uses financial incentives to encourage pumping and treatment of
groundwater that does not meet drinking water standards in order to protect water quality by
reducing the spread of poor-quality groundwater.
C7CWD �roundwater Nlanagement Pian 2015 Updat� ES7
Executive Summary
NATURAL RESOURCES AND COLLABORATIVE PROGRAMS
OCWD's collaborative efforts in the Santa Ana River Watershed include natural resource
programs to replace invasive plants with native plants and manage habitat for endangered
and threatened species. These programs protect the water quality in the Santa Ana River and
fulfill mitigation requirements for impacts to natural
'����� �` resources from District operations in the Prado Basin.
�
,;,��1� ;
�" ` During the 1960s, the U.S. Army Corps of Engineers
� , r�;
,.�� �y,f,�, �..
�. i,
began working with OCWD to conserve water behind
,
�
Prado Dam in order to support OCWD s groundwater
,<< ' recharge operations. OCWD's natural resource
programs began in response to concerns that increased
water storage behind the dam could negatively impact
the Prado Basin ecosystem.
` The Prado Basin contains the single largest stand of
forested riparian habitat remaining in coastal southern
� ;;:r.
California, which supports an abundance and diversity of
wildlife including many listed and sensitive species.
Habitat management programs in the Prado Basin are
responsible for the recovery of a federally endangered
ES-8 Least Bell's Vireo species, the least Bell's vireo, shown in Figure ES-8.
In addition to programs in the Prado Basin, the District is a partner in watershed-wide efforts
to eradicate the invasive plant Arundo donax, to manage habitat for rare and endangered
birds, and to protect the Santa Ana Sucker, an endangered fish. Wildlife protection programs
within Orange County include the construction of a bird island on Burris Basin and on-going
participation in programs to manage water resources in the watershed.
SUSTAINABLE BASIN MANAGEMENT
In the early 1950s, increased pumping from the basin outpaced the rate of recharge. Water
levels dropped and seawater intruded into coastal areas threatening the basin's water quality.
The District began purchasing imported water to recharge the basin.
Groundwater producers supported legislative changes to the OCWD Act that provided for
management of the basin as a common pool of water rather than allocating individual basin
water rights. The adopted legislation allowed all producers to pump as much as they wanted
provided that they pay for the costs of replenishing the basin. Sustainable management has
allowed for basin production to grow from less than 200,000 afy in the mid-1960s to over
300,000 acre-feet in the 2000s as shown in Figure ES-9.
The basin must be maintained in an approximate balance to ensure the long-term viability of
basin water supplies. In any given year, groundwater withdrawals may exceed water
OCWD Groundwater Management Plan 2015 tlpdate ES8
Executive Summary
recharged as long as over the course of a number of years this is balanced by years when
water recharged exceeds withdrawals. OCWD calculates the basin storage level annually and
sets the target amount of production to manage pumping to either increase or decrease
groundwater storage levels in response to hydrological conditions.
The primary mechanism used by OCWD to manage pumping is the Basin Production
Percentage (BPP). The BPP is a percentage of each Producer's water supply that comes
from groundwater pumped from the basin. The BPP is set on an annual basis and is uniform
for all Producers. Groundwater pumping above the BPP is assessed an additional charge that
creates a disincentive for over-producing.
The basin is managed to maintain water storage levels of not more than 500,000 acre-feet
below full condition to avoid permanent and significant negative or adverse impacts. The
basin is operated within a safe operating range as shown in Figure ES-10. Operating the
basin in this manner enables the District to encourage reduced pumping during wet years
when surface water supplies are plentiful and increased pumping during dry years to provide
additional local water supplies during droughts.
Groundwater Production
Acre-feet(x 1,000)
450 ; - --- -
400 � ---- - ------
�
350 ------ _______ _ �____
300 -�----___ __.__ ___.__.� �_
250 � __
200 � _—____. ------ -- ---------------
150 : —
100 ? ------
i
�
50 �-- --_ _ ----- _
0 -;--- , , , . , , _ f , , , . , , , . , , . ,
1963-64 1973-74 1983-84 1993-94 2003-04 2013-14
Water Year
Figure ES-9: Groundwater Production, Water Year 1963-64 to 2013-14
C?CWD Groundwater Man�gemer�t Piarr 2015 Update ES9
Executive Summary
Available Storage
(amount below full condition)
Acre-feet(x1000)
Amount of groundwater in
o - storage varies yearly;
so n managed within safe
100 pn, `° __
operating range
�,£ 4 �•/� �1
150 F �,.��" __ �
200 � � _ ,� � �
� " ��
� �
: �r� � ;,
250 ; ��� � ,,,.
x� �� �� c t
. it &{,� � �
g� Y�GP S}':�i5,, �h�'!"
300 � __ �k�
�. �
, �„'
.
350 � r �;��
� ,
� J�, �� --
400 �r �
; �`#�3,
���
450 ���''�'°�`'" � `�
500 �������,°�`,
1974-75 1978-79 1982-83 1986-87 1990-91 1994-95 1998-99 2002-03 2006-07 2010-11 2014-15
Water Year
Figure ES-10: Groundwater Storage for Water Years 1974-75 to 2013-14
Each year, the District determines the optimum level of storage for the following year when it
sets the BPP. This determination is affected by several factors, including the current storage
level, regional water availability, and hydrologic conditions. The District manages the basin
within an established operating storage range. When the basin storage approaches the lower
end of the operating range, issues that become more of a concern include seawater intrusion,
upwelling of amber-colored water into the Principal Aquifer from underlying aquifers,
downward migration of poor-quality groundwater from the Shallow Aquifer, increased risk of
land subsidence, and potential for shallow wells to become inoperable due to lower water
levels (see Figure ES-11). When operating the basin at a higher storage level, the amount of
energy required to pump groundwater is less but groundwater outFlow to Los Angeles County
may be greater.
One of OCWD's basin management objectives is to maximize groundwater recharge. This is
achieved through increasing the efficiency of and expanding the District's recharge facilities
and the supply of recharge water. Operation of the GWRS provides a substantial increase in
supply of water available to recharge the basin. Additional District supply management
programs include encouraging and using recycled water for irrigation and other non-potable
uses, participating in water conservation efforts, and working with the Metropolitan Water
District of Southern California and the Municipal Water District of Orange County in
developing and conducting other supply augmentation projects and strategies.
(JCWD Groundwater Management P(an 2015 Update ES10
Executive Summary
HIGHER+GROUMDV4IATER LEVELS ��
���.
Water available for pumping '
during droughts. �
�
�-, �
�; �
��-,� t� ,
�r
;,
,� �� � ��
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�
r � .��L�u���„ :�`� ���,��S.v�,�.
yh� t 'tfi. �i
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�
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`�° � � "` � Lower cost
x*�����k�� �`�°:°° �
�� �a� '� �,.� �
� �a������ � to pump
�a���������� groundwater.
aw� � . ,
��e�a�, �:�
,
° � . ,.
LOWER GROUNDWATER LEVELS �•'
Higher cost to pump groundwater.
Storage
Less water availabie for � space
pumping during droughts. � available
��, when
� > �:: recharge
�� supplies
,�y�r� �,� ° are
.,,.,3_ ,
� � � �
���
� �,��� � plentiful.
� "�� � �
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� kc
�y
�� �
��,�,� �
,�''� � �S���;�?�
�� � ? � �z� ,
ti
�h��� �a�r`�"� . ;����� ,._� �
��yvo�����e q�y�
� Z� ���e;..
z���r���� a
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�� ������������. Reduced yields in
��������" ' shatlow weils.
�,��
�,���.,
�.m�v ��
Figure ES-11: Impacts of Change in Groundwater Storage Levels
Financiai Management
The District's fiscal year begins on July 1 and ends on June 30. The annual operating budget
and expected revenues for FY 2014-15 were approximately$134.4 million. This includes a
budget of$26 million to purchase imported water for recharge. Revenue sources include
assessments to groundwater producers, property taxes, grants, and low-interest loans.
C�CWD Gro�ndwater Managemer�t Plan 2015 Update E511
HISTORYAND GOVERNANCE
.4�� �� �
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Recharge' aci ities, Ovirns r arrti"�neW. �n itia �ver w��h ,�vees, 1
The Orange County Water District, since its founding in 1933, has managed the
Orange Counfy Groundwater Basin. This section includes:
History of the Oranqe County Water District
1933: OCWD created by California legislature
1949: First purchase of imported water for groundwater recharge
1957: First off-river recharge basin purchased
1975: Talbert Seawater Barrier begins operation
2008: Groundwater Replenishment System beings operation
District Governance
• Board of Directors comprised of 10 members, each representing one division
• Groundwater Producers meet monthly with District staff
Public Events
• Groundwater Adventure Tours and GWRS Tours
• Children's Water Festival
• OC Water Summit
Section 1
History and Governance
CTIC� 1 I T Y A �°�/EFZ
1 .1 INT�(�D�JCTION �
The Orange County Water District (OCWD, the District) is a special district formed in 1933 by an
act of the California Legislature. The District manages the groundwater basin that underlies
north and central Orange County. Water produced from the basin is the primary water supply
for approximately 2.4 million residents living within the District's boundaries.
.j� �
� ,.. �a �,, °�� �
� 4 �
d,. .,�-��,�, ��:�. �,.». �h �
����`� �T 4 � �C� "*� � 'S�F ����t�`�}.,'S,�d.
� � . � � � � �'~��,'+ a��
r��
� ` , s �� � � �>.
,.;� , .� i, �5 ',�;�y
� ' Y� k . ', � ,�, .�.`&�
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> � ;�
�. °., �� ,�,.:
t� � �`� �+`s
� ��s
� .��,,, �� �
� �� r�^W���',/ � �i. ���
,. �
;
,h�
��
Figure 1-1: OCWD Board of Directors, circa 1935
Nineteen major groundwater producers, including cities, water districts, and private water
companies, pump water from about 200 large-capacity wells for retail water use. There are also
approximately 200 small-capacity wells that pump water from the basin. OCWD protects and
manages the groundwater resource for long-term sustainability, while meeting approximately 60
to 70 percent of the water supply demand within its service area.
Since its founding, the District has grown in area from 162,676 to 243,968 acres and has
experienced an increase in population from approximately 120,000 to 2.4 million people. The
District has employed groundwater management techniques to increase the annual yield from
the basin including operating over 1,500 acres of infiltration basins in the cities of Anaheim,
Orange, and unincorporated areas of Orange County. Annual water production increased from
approximately 150,000 acre-feet per year(afy) in the mid-1950s to a high of over 360,000 afy in
water year 2007-08.
OCWD has managed the basin to provide a reliable supply of relatively low-cost water,
accommodating rapid population growth while at the same time avoiding the costly and time-
OCWD Groundwater Management Plan 2015 Update 1-1
Section 1
History and Governance
consuming adjudication of water rights experienced in many other major groundwater basins in
Southern California. Facing the challenge of increasing demand for water has fostered a history
of innovation and creativity that has enabled OCWD to increase available groundwater supply
while protecting the long-term sustainability of the basin.
� .2 HIiTtJF�Y t�F T�M� aR��lG� CtatJ�l�'Y WATER Df�TRICT
1800S: Population in the Santa Ana River Watershed increases rapidly as immigrants move
into the region that for centuries was populated by Native Americans.
1900S: Growth of Orange County's agricultural economy creates demand for water, straining
available surface and groundwater supplies. Increased water use upstream in San Bernardino
and Riverside Counties results in declining flows in the Santa Ana River.
, __ . ..___. a _:.._ ; . .. 1932: The Irvine Company, the
�' ��' � county's largest landowner, files
� x.�, �,- _���'� �' �
� � . r ��'
�� ,� ,� ° suit against upper basin users to
r..�-�� '��a` � �� �-�"��-� -��"�` � � protect its rights to river flows.
� ��_; , ,. °� � �.. � �
The Orange County Farm
_�
� � ��� �� Bureau forms the Santa Ana
� � �,
� � � °� � �� � x ;�
� d� � ��' � �-� . �. � �` .�-;; � � � � Basin Water Rights Protective
� 'r�`��� ` � � � � � � `�"� �� Association to consider options
�� ,
�.
v � �k �x ��� . , ;� to secure adequate supplies.
. �. �
�- '> '- �'���
� .
'
. __ .. � Jut12 14, 1933: California
. � �� �,.,
.... , . - . ,�
��, _ ' � �'� � �-- � ��� Legislature creates the Orange
����
� . 'fE,� � .���� � ' � ��'' County Water District by special
� . :.
` �'�� � .�,_- �.- � � ; act to rotect surface water
' �` r i r ��� P
' �, � �`�� �` � � ' � ���.- � rights and manage the
- �� >�� ��' � �:r . '�� groundwater basin. The new
� �� �� - ���"=�� ��� � � � � " district joins the Irvine
„r,,,u,.>�.�. _„ �.. � _ .*
��a�'Co��� , � �� �� � � ��� �� Company's lawsuit.
��,��ae��rit�.� =.`��� �
`"" . x.>` ;-°� '� 1930S: Groundwater pumping
� � . .. . .. .. ., �
�_ ... �.. - CAI.IFORNM ` .
- � - s�w�.����.tiarza �' � ��'" ! � � � � � n m Orange County exceeds the
� �� � � � � rate of recharge resulting in
� � Figure 1-2: District B' `ndary, 1933
�°- ��- - •�- _ - - groundwater levels dropping.
OCWD begins actively recharging the groundwater basin and looking for additional water
supplies.
1936: OCWD begins purchasing portions of the Santa Ana River channel with the first
purchase of 26 acres.
OCWD Groundwater Management Plan 2015 Update 1-2
Section 1
History and Governance
1942: The Irvine Company lawsuit is settled by setting limits on the amount of Santa Ana
River water to be used for recharge in the upper basins as a means to provide Orange County
with a share of this water supply.
1949: OCWD begins purchasing imported water from the Colorado River Aqueduct for
groundwater recharge.
1951 : OCWD initiates legal action against cities upstream of Orange County to protect rights
to Santa Ana River flow. Settlement of the suit in 1957 limits use of river water to the amount
used in 1946.
1954: The District Act is amended giving OCWD authority to collect a Replenishment
Assessment(RA)from groundwater pumpers to purchase imported water for groundwater
recharge. The amendments also enlarged the District boundaries, and required the publication
of an annual engineer's report on groundwater production and basin conditions.
1956: Groundwater levels drop as much as 40 feet below sea level and seawater intrudes 3'/2
miles inland. Plans begin to construct seawater intrusion barriers in two areas—Alamitos Gap at
the mouth of the San Gabriel River at the Orange County/Los Angeles County border and the
Talbert Gap at the mouth of the Santa Ana River in Fountain Valley.
1957: OCWD purchases land and constructs Anaheim Lake, the District's first off-river
recharge basin. , .�; Aa
A" + 1 • �
�55
1963: OCw�f�es a
lawsuit against all upper
watershed entities above
Prado Dam to ensure a
minimum amount of
Santa Ana River water
for Orange County.
1965: OCWD partners
with the Los Angeles
County Flood Control , �r���,��
District to begin injecting ' Y
�� y�~
fresh water into the -�� ��
Alamitos Gap to prevent � �p�
saltwater intrusion. " ,,�`����}
1968: OCWD purchases land and water rights owned by Anaheim Union Water Company and
the Santa Ana Valley Irrigation Company, which includes land upstream of Prado Dam that was
acquired to protect Orange County's interest in Santa Ana River water.
OCWD Groundwater Management Plan 2015 Update 1-3
Section 1
History and Governance
1969: The lawsuit against upper watershed entities is settled. (Orange County Water District
v. City of Chino, et al., Case no. 117628 —County of Orange). Large water districts agree to
deliver at least 42,000 acre-feet of Santa Ana River baseflow to Orange County and OCWD
gains the rights to all stormflows reaching Prado Dam. Parties to the judgment include Western
Municipal Water District, San Bernardino Valley Municipal Water District and the Inland Empire
Utilities Agency.
1969: The Basin Production Percentage and the Basin Equity Assessment are established.
1973: First water quality laboratory is constructed to analyze samples from the Santa Ana
River and to begin analysis of demonstration injection wells for the planned construction of
Water Factory 21.
1975: Talbert Seawater Intrusion Barrier begins operation. Control of seawater intrusion in the
Talbert Gap requires six times the amount of water needed for the Alamitos Gap. Water
Factory 21 is built to supply water to the Talbert Seawater Intrusion Barrier. Secondary-treated
wastewater from the Orange County Sanitation District receives advanced treatment and is
blended with potable water to produce a safe, reliable supply for barrier operations.
� � , ('���`w.�. !�„
� � �. a.
���a ,.�°�'"'����.�:�''"�-:.^ ",��,� ���
.�-�^, � ° � a� ,
� „ � � -. � �' � .
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<
�.�'.�°�.�:,��, .�r«�.�,,..�» �p,1�
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t„ ' iw'�' � � 'c� � �
a,�� y
��"� Sti ,�., 1. `��
,� Mi'., '�,.
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� �
�� ��^� ���
,�
� �"��,�`„,"�``" �,.
� ����� . ,,
�� �.
i� � � �
� , ,.
f �
�� � u
��� �... � , � � � �
>,,�� �, � � � � ,�,
Figure 1-4: Water Factory 21, circa 1975
1991 : Santiago Creek recharge project is completed, including purchase and development of
Santiago Basins along Santiago Creek, a pump station at Burris Basin, and a pipeline to convey
water back and forth from recharge basins along the Santa Ana River and Santiago Basins.
Two rubber dams are installed on the Santa Ana River, allowing for more efficient diversion of
river water to the downstream recharge facilities. The increased capture of water from the dams
paid for the cost of the dams within the first year of operation.
OCWD Groundwater Management Plan 2015 Update 1-4
Section 1
History and Governance
2008: The Groundwater Replenishment System (GWRS) begins operation, replacing Water
Factory 21. The GWRS is capable of producing up to 72 mgd of water for use in Talbert Barrier
operations and for groundwater recharge.
2009: New Advanced Water Quality Assurance Laboratory opens to handle over 400,000
analyses of nearly 20,000 water samples each year.
2015: GWRS Initial Expansion is completed, expanding plant capacity from 72 mgd to 100
mgd of product water.
Figure 1-5: GWRS Reverse Osmosis Building
1 .3 OGWD GOVERNA�IC�
The Orange County Water District was created by a special act of the California legislature in
1933 for the purpose of:
"providing for the importation of water into said district and preventing waste of
water in or exportation of water from said district and providing for reclamation of
drainage, storm, flood and other water for beneficial use in said district and for
the conservation and control of storm and flood water flowing into said district;
providing for the organization and management of said district and establishing
the boundaries and divisions thereof and defining the powers of the district,
including the right of the district to sue and be sued, and the powers and duties of
the officers thereof; providing for the construction of works and acquisition of
property by the district to carry out the purposes of this act; authorizing the
incurring of indebtedness and the voting, issuing and selling of bonds and the
levying and collecting of assessments by said district; and providing for the
OCWD Groundwater Management Plan 2015 Update 1-5
Section 1
History and Governance
inclusion of additional lands therein and exclusion of lands therefrom."
(Stats.1933, c. 924, p. 2400)
The District is divided into 10 divisions as specified in the District Act. One director is elected or
appointed from each division. The cities of Anaheim, Fullerton, and Santa Ana appoint one
member each to serve on the Board. The other seven Board members are elected by voters in
the respective divisions. Boundaries of the 10 divisions are shown in Figure 1-6. Appointed
members of the Board serve a four-year term and may be removed at any time by a majority
vote of the appointing governing body. Elected members of the board serve four-year terms
and may be re-elected without limits.
,¢���� � ��
LOS ANGELES �"�� �a.�;d'�"" �� �,,f�y �», �.��`� �:k���'�s ff,y,,.
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Figure 1-6: Board of Directors Service Area
OCWD Groundwater Management Plan 2015 Update 1-6
Section 1
History and Governance
The ten divisions are comprised of the following areas:
Div'tsion One: Garden Grove, Stanton, Westminster
Division Two: Orange, Villa Park, and parts of Tustin
Division Thres: Buena Park,La Palma, Placentia, Yorba Linda, and parts of Cypress
Division Four: Los Alamitos, Seal Be�ch, and parts of Buena Park, Cypress, Garden
Grove, Huntington Beach, Stanton, and Westrninster
Division Five: Parts vf Irvine and Newport Beach
Division Six: Parts of Fountain Valley and Huntington Beach
Division Seven: Costa Mesa and parts of Fountain Valley, Irvine, Newport Beach and Tustin
Division Eight: Santa Ana
Division Nine: Anaheim
Division Ten: Fullerton
The full Board of Directors, shown in Figure 1-7, meets twice a month, normally on the first and
third Wednesdays of the month. Board committees also meet on a monthly basis. These
committees include the Water Issues, Communication/Legislation, Administration/Finance,
Property/Management and Retirement:
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Figure 1-7: OCWD Board of Directors Meeting in Fountain Valley
OCWD Groundwater Management Plan 2015 Update 1-7
Section 1
History and Governance
The Groundwater Replenishment System Steering Committee, a joint committee of OCWD and
Orange County Sanitation District (OCSD) meets on a quarterly basis to manage and plan
operation of and expansion of the Groundwater Replenishment System. As operation of the
plant is a joint venture of the two agencies, the Steering Committee discusses issues such as
flow availability from the OCSD plant, operational challenges, plant expansion, source control,
water quality, and others.
Section 2 of the District Act grants powers to the District as summarized below:
• To construct, purchase, lease, or otherwise acquire, and to operate and maintain necessary
waterworks, water rights, spreading grounds, lands, and rights necessary to replenish the
groundwater basin and augment and protect the water quality of the common water
supplies of the District;
• Provide for the conjunctive use of groundwater and surface water resources within the
district area;
• Store water in underground basins or reservoirs within or outside the District;
• Regulate and control the storage of water and the use of groundwater basin storage space
in the basin;
• Purchase and import water into the District;
• Transport, reclaim, purify, treat, inject, extract, or otherwise manage and control water for
the beneficial use of persons or property within the District and to improve and protect the
quality of the groundwater supplies;
• Determine the amount and percentage of water produced from the groundwater basin
within the district to the total amount of water produced within the District by all persons and
operators;
• Require that persons and operators produce more or less of their total water needs from the
groundwater within the District than the basin production percentage determined by the
District, levy a basin equity assessment on each person and operator who produces more
water from the basin, compensate persons and operators who are directed by the District to
produce less than the basin production percentage;
• Provide for the protection and enhancement of the environment within and outside the
District in connection with the water activities of the district; and
• To commence, maintain, intervene in, defend, and compromise, and assume the costs and
expenses of all actions to prevent interference with water or water rights used within the
District or diminution of the quality or pollution or contamination of the water supply of the
District.
A copy of the District Act can be found at:
http://www.ocwd.comlPortals/0/Pdf/ocwd district act.pdf.
OCWD Groundwater Management Plan 2015 Update 1-8
Section 1
History and Governance
1 .4 GRC�UND1dVVATER PRC�DUCER�
The local agencies that produce the majority of the groundwater from the basin are listed in
Table 1-1 with geographic boundaries shown in Figure 1-8. District staff members meet
monthly with 19 local, major water producers, referred to as the Producers, to discuss and
evaluate important basin management issues in order to involve other affected agencies and
work cooperatively where service areas or boundaries overlie the basin.
Table 1-1 Major Groundwater Producers within OCWD Boundaries
CITIES
Anaheim Huntington Beach Santa Ana
Buena Park' La Palma Seal Beach
Fountain Valley Newport Seach Tustin
Fullerton Orange W+�stminster
Garden Grove
WATER DISTRICTS AND WATER COMPANIES
East Orange County Water bis#rict Mesa Water District
Golden State Water Gompany Serrano Water District
Irvine Ranch Vllafer District Yorba Lincfa Wa#er Distric#
Generally, each year a chairman is elected to manage the Producers' meetings and represent
the Producers. This monthly meeting provides a forum for the Producers to provide their input
to the District on important issues such as:
• Setting the Basin Production Percentage (BPP) each year;
• Reviewing the merits of proposed capital improvement projects;
• Purchasing imported water to recharge the groundwater basin;
• Reviewing water quality data and regulations;
• Maintaining and monitoring basin water quality; and
• Budgeting and considering other important policy decisions.
OCWD Groundwater Management Plan 2015 Update 1-9
Section 1
History and Governance
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Figure 1-8: Retail Water Agencies within OCWD
1 .5 PUB�IC EDUCATION AND EVENTS
Proactive community outreach and public education are central to the operation of OCWD. The
District is dedicated to the creation, promotion and management of water education and
conservation programs throughout Orange County. Each year, staff members give more than
70 offsite presentations to community leaders and citizens, conduct nearly 200 onsite
presentations and tours of District facilities, and take an active part in community events (see
Figure 1-9). The goal of OCWD's water-use efficiency and education programs, local water
briefings, and outreach to organizations is to draw attention to state and local water needs and
crises, teach useful and simple ways to reduce water consumption and respect this natural
resource, and encourage local citizens to make life-long commitments to conserving water. The
components that comprise OCWD's water-use efficiency, outreach and public education events
and programs are described in this section.
OCWD Groundwater Management Plan 2015 Update 1-10
Section 1
History and Governance
Children's Water Education Festival
The Children's Water Education Festival, shown in Figure ?-9, is the largest event of its kind in
the nation, serving approximately 7,000 elementary school students annually. Thanks to more
than 400 volunteers and the support of the Disneyland Resort, the National Water Research
Institute and OCWD's Groundwater Guardian Team, the Festival celebrated its 19th anniversary
in March 2015. The two-day Festival teaches children about water and the environment through
hands-on educational activities. Topics include water resources, watersheds, wildlife and natural
habitats, biology, chemistry and recycling at this unique event.
The Festival has a legacy of hosting educational presenters who are experts from organizations
such as National Geographic, NASA/JPL, Columbia Memorial Space Center, Wyland
Foundation, California Department of Water Resources, United States Environmental Protection
Agency, United States Army Corps of Engineers, UCLA, and UCI. Since inception, more than
110,000 students have attended.
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Figure 1-9: Group Attending the 2015 Children's Water Education Festival
O.C. Water Hero Pro_qram
The O.C. Water Hero Program was designed to make water conservation fun while helping
children and parents develop effective water-use efficiency habits that will last a lifetime. When
children sign up to commit to saving 20 gallons of water per day, they will enjoy videos, games,
trivia, and other incentives they can access via the website and smartphone applications. The
OCWD Groundwater Management Plan 2015 Update 1-11
Section 1
History and Governance
purpose of the O.C. Water Hero Program is to raise awareness of the need to conserve water
and motivate county residents to reduce their water consumption by 20 gallons per day, per
person. Since its inception in 2007, nearly 20,000 Water Heroes and Superheroes have enrolled
in the program. In 2015, OCWD revamped the program to upgrade the technology platForm in
order to increase participation.
Groundwater Guardian
The District was recognized as a Groundwater Guardian member in 1996, thereafter forming the
OCWD Groundwater Guardian Team. This program is designed to empower local citizens and
communities to take voluntary steps toward protecting groundwater resources. The OCWD
Groundwater Guardian Team primarily supports the Children's Water Education Festival.
Social Media
Social media is a unique opportunity to provide information directly to people interested in
OCWD and the topics associated with the organization. Through vehicles such as Facebook,
Twitter, YouTube, Instagram and others, the District posts information of immediate importance,
as well as joins the conversation on trending topics. OCWD engages in social media practice
several times during a given week, primarily to followers of its Facebook and Twitter accounts.
OC Water Summit
The annual OC Water Summit, shown in Figure 1-10, teaches individuals, business, and
community and civic leaders where our water comes from, and provides information about the
water supply crisis and water quality challenges we face. The event, held annually since 2008,
educates the public on what temporary measures are in place to address these issues as well
as possible solutions to water reliability and preserving the Bay-Delta River, California's main
source of water. A collaborative effort between businesses, water agencies and local
governments, the OC Water Summit provides a platform for individuals in the community to
work with water utilities and
legislators on creating and �`�
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Orange County and the
Disneyland Resort.
Figure 1-10: 2014 Orange County Water Summit
OCWD Groundwater Management Plan 2015 Update 1-12
Section 1
History and Governance
The Groundwater Adventure Tour
Nearly 150 guests attend the Groundwater Adventure Tour(see Figure 1-11) that takes place
each fall. The annual event highlights Orange County Water District operations that include the
Groundwater Replenishment System, the Advanced Water Quality Assurance Laboratory,
Recharge Operations, and Prado Wetlands. The day's activities are designed to provide an
inside look at Orange County's water supply, as well as provide a better understanding of the
District's groundwater recharge operations.
Tour attendees include staff from cities, o�ces of elected officials, water districts, universities,
state and county agencies, students, chambers of commerce members, service club members,
and other stakeholders. Information is presented to attendees in a variety of formats including
speeches, tours, video and question and answer sessions. OCWD executive management and
supporting staff share their knowledge and facilitate activities throughout the day.
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Figure 1-11: 2014 Groundwater Adventure Tour
Website
The Public Affairs Department hosts the District's website, www.ocwd.com, to provide
information on an array of subjects about OCWD, its board, facilities, and its programs. It
includes access to important documents and forms providing transparency and public access.
In 2015, the District merged the OCWD website with a separate site that was dedicated to
information about the Groundwater Replenishment System, www.gwrsystem.com . The website
helps to engage the citizens of north and central Orange County and water-related agencies to
learn more about OCWD's operations.
Hydrospectives Newsletter
The Hydrospectives newsletter is a monthly publication with a circulation of approximately 5,700
subscribers from the water industry, government officials and agencies, OCWD staff, and the
general public. It reflects the progress and decisions of the District, its achievements and
influences and information pertinent to the groundwater industry in north and central Orange
OCWD Groundwater Management Plan 2015 Update 1-13
Section 1
History and Governance
County. Each month, it offers a variety of subjects that include a message from the board
president, important contributions from departments and staff, global and regional news, and
celebrations and accomplishments of which OCWD is a part.
Media Coveraqe/Exposure
OCWD, its facilities and programs have been featured in thousands of print and broadcast
stories, both mainstream and trade press, locally, nationally and internationally. The District and
its Groundwater Replenishment System have been featured in National Geographic magazine,
Wall Street Journal and on the 60 Minutes television program. They have also been featured in
several documentaries including "Tapped —The Movie;" "Ecopolis" and "How Stuff Works"for
Discovery N; "Urban Evolution: The Story of Pure Water"for London's Institution of
Engineering &Technology; "America's Infrastructure Report Card-Wate�" (ASCE 2009); in an
episode of"Off Limits"for the Travel Channel; and referenced in the documentary titled "Last
Call at the Oasis."
Facility Tours and Speakers Bureau
OCWD receives hundreds of requests each year to provide tours and briefings for visitors from
local colleges, water agencies, the surrounding community, and international organizations.
Through its active speakers bureau program, OCWD also receives requests for representatives
to go out to the community and speak to numerous organizations and schools, as well as at
local, national and international conferences.
Since the GWRS came online in January 2008, more than 24,000 visitors have toured the
facility. During FY 2013-14, OCWD conducted 198 public tours of the GWRS plant and the
Advanced Water Quality Laboratory with a total of 3,432 �articipants.
OCWD is committed to p�oactive public outreach and education and makes every effort to
accommodate requests for speakers and tours. Educating the public about advanced
wastewater purification
is important to �������,����� ������ � �
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water supply
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groundwater supplies. Figure 1-12: OCWD Public Tour
OCWD Groundwater Management Plan 2015 Update 1-14
PREPARATION OF GROUNDWATER
MANAGEMENT PLAN
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The Groundwater Management
Plan is a comprehensive
description of and plan for
District operations. This section
includes:
History of the District's Groundwater Management Plan
• First plan adopted in 1989 under authority granted by OCWD District Act
• 2015 Update will be sixth updated plan
• CA Sustainable Groundwater Management Act elements incorporated into
2015 Update
Goals established for Basin Management Objectives
• Protect and enhance groundwater quality
• Protect and increase basin sustainable yield in cost-effective manner
• Increase operational efficiency
Accomplishments 2009 to 2014
• Status of 2009 recommendations
• 19 completed projects
Recommendations for 2015 to 2020
Section 2
Preparation of Groundwater Management Plan
�EC�IC�N 2 F'REP�RATI�N C�F GR�UN�V'VATER
�V1AN���14��NT PLAN
�.� ��s�ROD��T�o�
OCWD adopted its fi�st Groundwater Management Plan (GWMP) in 1989 under authority
granted by the District Act. Updates to the plan were prepared and adopted by the Board of
Directors in 1990, 1994, 2004, and 2009.
The 2015 update sets forth basin management goals and objectives, describes
accomplishments, explains changes in basin management, and provides information about
projects completed by the District since publication of the latest update in 2009. OCWD's goals
and basin management objectives were reviewed and revised as necessary reflecting the need
to protect and manage the Orange County Groundwater Basin for long-term sustainability.
The District, as the groundwater basin manager, and the Producers, as the local retailers,
cooperate to serve the 2.4 million residents within OCWD's boundaries. The OCWD's Board of
Directors and the Producers served as the Advisory Committee for the preparation of this
Groundwater Management Plan. The OCWD Board of Directors has the sole authority to adopt
the GWMP.
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� � �� OCWD Staff with
Groundwater Producers
Specific projects developed as a result of recommendations in the GWMP are separately
reviewed and approved by the District's Board of Directors and processed for environmental
review prior to project implementation. The GWMP describes the factors and key issues that
are considered as the Board makes basin management decisions on a regular basis each year
but does not commit the District to a particular program or level of groundwater production.
To encourage public participation in the development of and adoption of the GWMP update,
OCWD published a notice pursuant to Section 6066 of the Government Code of the District's
intention to prepare this document and invited interested individuals to participate in the
preparation process. A notice was placed on OCWD's website on the main page inviting public
participation.
In addition to the publicly-noticed public participation opportunities and postings on the website,
the District held workshops with the Producers, shown in Figure 2-1. The Producers include
OCWD Groundwater Management Plan 2015 2-1
Section 2
Preparation of Groundwater Management Plan
cities, special districts and investor-owned utilities that produce more than 90 percent of the
water pumped from the basin. The content of the GWMP was developed with input and review
from the Producers by conducting workshops and seeking comments on drafts of the plan.
The California Water Code (section 10750 et seq.) describes the process for development and
adoption of a groundwater management plan that includes a public participation component. As
explained above, the process of adopting this plan included publicly-noticed meetings held as
part of the District's regularly-scheduled board meetings and information posted on the OCWD
website and the Hydrospectives newsletter. Appendix A contains copies of the public notices.
Water Code Section 10753.7 and 10753.8 lists the mandatory and recommended components
of a Groundwater Management Plan. A complete list of these components and their location in
the OCWD's GWMP can be found in Appendix B. This plan is developed to meet the
requirements of the California Water Code.
2.2 SUSTAINABL.E C�RC}UNDWATER MA�IAGE ENT �CT
The California Sustainable Groundwater Management Act (SB1168, AB1739, and SB1319)
became law on September 16, 2014. This new law provides specific authority to establish
groundwater sustainability agencies and sets forth procedures and requirements to prepare and
adopt Groundwater Sustainability Plans.
The new law establishes OCWD as the exclusive local agency to manage groundwater within
the District's statutory boundaries with powers to comply with the provisions of the Sustainable
Groundwater Management Act (California Water Code Section 10723 (c) (1)).
California Water Code Sections 10727 (a) and 10733.6 require groundwater sustainability
agencies to develop and implement groundwater sustainability plans and submit the plans to
DWR for review upon adoption. Section 10733.6 also provides for the preparation of an
alternative plan that includes an analysis of basin conditions demonstrating that the basin has
operated within its sustainable yield over a period of at least 10 years. An alternative plan must
be submitted no laterthan January 1, 2017.
DWR is required to adopt regulations by June 1, 2016 for evaluating groundwater sustainability
plans and the implementation of plans. Regulations shall identify necessary plan components
(California Water Code Sections 10727.2, 10727.4 and 10727.6). Required elements include a
description of the physical setting and characteristics of the aquifer system, measurable
objectives, a planning and implementation horizon, components related to management of the
basin, summary of monitoring programs, monitoring protocols, and a description of how the plan
may affect other plans related to water resources.
Required elements for Groundwater Sustainability Plans and additional plan elements have
been incorporated into OCWD's Groundwater Management Plan. These elements are listed in
Appendix B along with references to where the elements are contained in in the plan. A
description of how each of the basin management objectives contributes to sustainable
management of the basin can be found in Appendix C.
OCWD Groundwater Management Plan 2015 2-2
Section 2
Preparation of Groundwater Management Plan
2.3 BA��N MANGEIVlE�9T� G�JALS AND OBJE�TIVES
OCWD basin management goals are:
1. To protect and enhance the groundwater quality of the Orange County Groundwater
Basin
2. To protect and increase the sustainable yield of the basin in a cost-effective manner
3. To increase the efficiency of OCWD operations
More specific basin management objectives set to accomplish the above mentioned goals are
summarized below in Table 2-1, 2-2, and 2-3. A section reference is provided for each of the
objectives with detailed explanations of how the groundwater basin is managed to achieve the
objective.
Table 2-1: Basin Management Objective:
Protect and Enhance Groundwater Quality Section Reference
Groundwater Quality
Collect& analyze water quality samples from 400 District monitoring wells as
determined by program protocols (at least annually) 4'2
Collect & analyze water quality samples from 200 drinking water wells as determined
by Title 22 protocols (at least annually) 4'2
Recharge Water Supplies
Collect 8� analyze water quality samples of recharge supplies (surface, recycled, 4.2.5
imported, 8� ground water) according to program protocols (at least quarterly) 4.3
Surface Water Supplies
Sample &analyze 2 sites on Santa Ana River in Orange County as directed by 4.3
NWRI Santa Ana River Monitoring Program Expert Panel (quarterly)
Sample & analyze 12 sites in upper watershed for constituents as directed by NWRI
Santa Ana River Monitoring Program Expert Panei (annually) 4.3
Contamination Prevention and Remediation
Implement the District's Groundwater Quality Protection Policy 8.1
Evaluate & implement projects to address groundwater contamination in North Basin g.g
OCWD Groundwater Management Plan 2015 Update 2-3
Section 2
Preparation of Groundwater Management Plan
Table 2-1 : Basin Management Objective:
Protect and Enhance Groundwater Quality sect�on r�eference
& South Basin areas
Seawater lntrusion
CoNect samples &analyze water quality from 86 welfs to assess control of seawater 4 2, 7
intrusion at Talbert, Bolsa, Sunset, and Alamitos Gaps (annualfy)
Prepare Talbert Gap area chloride concentration contour maps{every two years) 7
Operate Talbert Seawater Intrusion Barrier to (1) maintain protective groundwater
elevation at well OCWD-M26 and (2) prevent landward seawater migratian into the 7.2
groundwater basin based on 250 mg/L chloride concentration contour
Participate in Alamitos Barrier Operations Committee to review barrier performance 7 3
(at least annuafly)
Operate Alamitos Seawater intrusion Barrier with Los Angeles County agencies to
prevent landward seawater migration into the groundwater basin based an 250 mg/L 7.3
chloride concentration contour
Increase injection or implement other measures to prevent basin degradation if �
significant seawater intrusion occurs
Wetlands &Natural Resources
Support natural resource programs in wa#ershed to improve water quatity 9
Participate in cooperative efforts with regulators and stakeholders within watershed 4.3:3, 9
Divert 50% of Santa Ana River flow through Prado Wetlands to improve river water 8 5
quality; measure flow& nitrogen removaf 1oads {monthly)
OCWD Groundwater Management Plan 2015 Update 2-4
Section 2
Preparation of Groundwater Management Plan
Table 2-2: Basin Management Objective:
Protect and Inerease Basin Sustainable Yield in Cost-Effective section
Manner
Reference
Collect & analyze at Ieast 1,�00 measurements of groundwater levels (at least 6
times/year) 4'2'2
Calculate change in basin storage (annually) 4.2.2
Collect production rate data from 19 large producers (monthly) 8�small producers
(every six months) 4.2.1
Participate in state CASGEM program by reporting groundwater elevation 4.2.4
measurements from 38 wells (annually)
Maintain groundwater storage within safe operating range (less than 500,000 acre- 10
feet below full condition)
Set target level for total production, estimate total water demands &establish Basin
Production Percentage (annually) 3.4, 10.2
Calculate total volume of water recharged (annually) 5
Report& publish, on website, total water recharged in Water Resources Summary 5
(monthly)
Convene OCWD Recharge Enhancement Working Group (annually) 5.5.1
Evaluate potential new recharge projects using District's Recharge Facilities Model 5.5.2
Promote local infiltration of stormwater 3.3.2
Participate in cooperative efforts with regulators &stakeholders in watershed 9.2, 9.3
Cotlect 8� review ground surface elevation measurement data from Orange 3.6
County Surveyor (annually)
If significant levels of subsidence occur, conduct characterization & mitigation study 3.6
Produce 90,000 afy of GWRS recycled water 6
Publish the Engineer's Report that includes total pumping, groundwater
elevations, change in storage, 8� related water data (annually) 10.2
OCWD Groundwater Management Plan 2015 Update 2-5
Section 2
Preparation of Groundwater Management Plan
Table 2-3: Basin Management Objective:
Increase Operational Efficiency sect�on Reference
Maintain Water Resources Management Sys#em database as centraf repository for 4.4
wate�quality, pumping, recharge, & related water management information
Manage District's finances for long-term fiscal stability 11
Operate District programs in cost-effective & efficient manner 41
Manage natural resource programs in Santa Ana River Watershed in efficient 9 2
manner
Implement efficient environmental management programs to reduce greenhouse 6.3
gas emissions & use'altemative energy where feasible
Use Recharge Facilities Model to evaluate cost-effectiveness of potential new 5.5
recharge basins &improvements to existing facilitias
Make improvernents to recharge facilities to increase efficiency 5.6
The District publishes the following reports to support achievement of the above listed
management goals:
• Update the Groundwater Management P/an every five years
� Update the Long-Term Facilities Plan periodically approximately every five years
• Publication of:
o Santa Ana River Water Quality Moniforing Report(biannually)
o Engineer's Report on the Groundwater Conditions, Water Supply and Basin
Utilizafion (annually)
o Santa Ana River Watermaster Report(annually)
o Groundwater Replenishment System Annual Report
• Preparation of the Water Resources Summary(monthly)
• Periodic publication of Report on Groundwater Recharge in the Orange County
Groundwater Basin
OCWD Groundwater Management Plan 2015 Update 2-6
Section 2
Preparation of Groundwater Management Plan
2.4 RECUMM�NDATIC�NS AND PROJECTS COMPLETED 2009-2015
In the 2009 GWMP Update, the District adopted recommendations to continue sustainable
management of the basin. Those recommendations that have been achieved are listed in Table
2-4. Recommendations yet to be completed are listed in Table 2-5. The tables indicate which of
the three basin management objectives (1) protecting and enhancing water quality, (2)
protecting and increasing the basin's sustainable yield, and (3) increasing the efficiency of
OCWD's operations apply to each of the recommendations. Table 2-6 lists the projects
completed by OCWD between 2009 and 2015.
Sustain-
Table 2-4: 2009 Recommendations: Completed water able Er��-
Quality Yield iency
Monitor groundwater elevations &water storage levels ✓ ✓
Monitor quality of groundwater 8� recharge water sources ✓
Update the Groundwater Management Plan ✓ ✓ ✓
Update the Long-Term Facillties Plan ✓ ✓ ✓
Publish annually: Santa Ana River Wafer Qualify; Engineer's Report; ✓ ✓ ✓
Santa Ana River Watermaster Report; GWRS Operations Annual
Report
Publish Report on Managed Aquifer Recharge ✓
Monitor water management& recycling plans in watershed ✓ ✓
Complete study on reducing sediment loads in recharge water ✓ ✓
Complete GWRS Initial Expansion ✓ ✓
Increase drought preparedness by utilizing full capacity of GWRS ✓
Develop improved tools and approaches to evaluate potential new ✓ ✓
recharge basins 8� proposed changes to existing operations
Expand removal of non-native vegetation 8� plant native vegetation ✓ ✓
Promote incidental recharge ✓
Manage recharge supplies to meet/exceed MCLs & Notificatio� Levels ✓
Operate Prado Wetlands to reduce nitrogen loads in Santa Ana River ✓
Publish research study on emerging constituents with MWD and NWRI ✓
OCWD Groundwater Management Plan 2015 Update 2-7
Section 2
Preparation of Groundwater Management Plan
Sustain-
Table 2-4: 2009 Recommendations: COmpleted water ab�e E��-
Quality Yieid iency
Participat� in coaperative efforts with watershed stakeholders ✓ ✓
Maintain control of seawater intrusion in the Talbert Gap ` ✓ �
Open new water quality laboratory in Fountain Valley ✓
Operate basin within safe&sustainable operating range ✓
Set Basin Production Percentage to optimize sustainable use of �
groundwater
Manage finances to tnaintain high credit ratings �
Maintain reserves for purchase of supplemental`water supplies ,�
Sustain-
Table 2-5: 2009 Recommendations On-going wate� ab�e Er��-
Quality Yield ency
Complete North Basin Groundwater Protectiorr Program ✓
Complete South Basin Groundwater Protection Program ✓
Address MTBE contamination ✓
Increase allowable storage of stormwater behind Prado Dam ✓ `✓
lmprove performance of Alamitos Seawater Barrier, evaluate need for ✓ ✓
more injection wells; construct necessary facifities
OCWD Groundwater Management Plan 2015 Update 2-8
Section 2
Preparation of Groundwater Management Plan
Table 2-6: Completed Projects/Accomplishments section
2009-2015 Completed Reference
GWRS Initial Expansion: expand'capacity from 70-100 mgd 2015 8
Miraloma Basin: new basin increased recharge by approx. 30,000 afy 2012 5.6
Construction of new water quality laboratory 2009 4.5
Olive Basin Pump Statiom increase infiltration by 1,600-4,800 afy 2010 5.6
Burris 8� Lincoln Basins Reconfiguration: remove impermeable material to 2010 5.6
increase infiltration rates
Santiago Basin Pump Station: remove water stored below outlet structure; 2012 5.6
increase of recharge capacity by 5,000 afy
Alamitos Barrier Flow and Transport Models to improve evaluation of 2014 3.7.5,
seawater intrusion 7.3
Recharge Facitities Model: evaluate existing 8� proposed operations to 2009 5.2.2
increase operationat efficiency
Santa Ana River Armoring Study of river sediments to evaluate 2010 5.5
alternatives for improved infiltration
Recharge Water Sediment Removal Feasibility Study: pilot-study of filter 2010 5.6
systems to improve percolation rates
Arundo Rernoval and NativePlantings: remove 5,000 acres of invasive 2014 9.2.2
plants; increase annual wa#er yield of 3.75 cfs/acre removed
Least Bell's Vireo Habitat Management: increase populations in watershed 2014 9.2.1
Nesting Box Installation; 500 boxes in Prado Basin & Forebay to attract 2014 9.2
birds that eat insect pests to reduce pesticide use
Regulatory approvaf to inject 100% recycled water at Talbert Barrier 2009 7.2
Adoption of a BPP Policy to assure long-term basin sustainability 2013 10.4.2
GWRS Plant Operational Optimization 2013 6.3
NWRI/MET/OCWD Study of constituents of emerging concern 2010 8.8
Completed testing for unregulated chemicals under the EPA UCMR!-List 1
program 2010 4.2.3
OCWD Groundwater Management Plan 2015 Update 2-9
Section 2
Preparation of Groundwater Management Plan
2.5 REC4M EN�ATIC) S FOR 201�-2�20
OCWD plans for the next five years include accomplishment of the recommendations
listed in Table 2-7.
Table 2-7: Recommendations for 2015 2020
PROJECT BENEFIT TO BASIN
GWRS Final Expansion to 130 MGD Increase recharge water supply from
100,OQ0 #0134,000 afy
Mid-Basin Injection Increase basin recharge in area of
concen#rated groundwater pumping
Subsurface Recharge & Collection System Increase recharge
Prado Basin Sediment Management Rsmove sediment behind darn to increase
Demanstration Project storage capacity
North Basin Groundwater Protection Remediate VOC contamination
Pragram
South Basin Groundwater Protection Remediate VOC contamination
Program
MTBE Investigation and Remediation Remediate MTBE contamination
Fletcher 8asin New recharge basin
West Orange County Enhanced Pumping Reduce groundwater flow from Orange
County into Las Angeles County
La Palma Basin New recharge basin
Prado Basin Enhanced Water Inerease allowable storage of stormwater
Conservation behind'Prado Dam
Increase recharge in Santiaga Creek
below Hart Park Increase recharge capacity
Alamitos Barrier Irnprpvements Protect water quality by increasing seawater
intrusion faciiities
Alamitos Barrier Expansion (Landing Hill) Expand seawater intrusic�n faailities
Sunset Gap BarrierlDesaiter �mprove water quality by capturing and
treating brackish groundwater
OCWD Groundwater Management Plan 2015 Update 2-10
Section 2
Preparation of Groundwater Management Plan
Table 2-7: Recommendations for 2015-2020
PROJECT BENEFIT TO BASIN
Huntingtan Beach Ocean Desalina#ion Increase water supply by up#0 56,000 afy
Piant
Enhanced Recharge in SAR Below Ball Increase capacity to capture and in�ltrate
Road stormwater
2.6 PLAI�NING AND IMPLEMENTATI4N HC?RiZQNS
District management and operations incorporate a variety of planning and implementation
horizons as explained below.
The Long-Term Facilities Plan is updated approximately every five years to evaluate a large
number of potential future projects. The planning horizon for consideration of new facilities is
five years. The implementation horizon for projects varies from finro to 10 years, depending on
size and complexity of the individual project. The 2014 plan, for example, evaluated 64
potential projects ranging from those to increase water supply, institute changes in basin
management, modify recharge facilities, and increase operational efficiency. Each proposed
project is considered for future study based on cost-effectiveness, amount of new water supply
provided, regulatory and institutional feasibility, and other factors. The cost-effectiveness of
each project that provides additional groundwater recharge is evaluated in relationship to the
current and projected cost of imported water. In this sense, the cost of imported water provides
a benchmark for determination of project cost effectiveness.
The District's Groundwater Management P/an is updated approximately every five years. This
plan provides an overview of all district operations, documents accomplishments and projects
built since the last updated plan was published, and establishes basin management objectives.
OCWD uses a variety of models and studies to assist in long-term planning. The Recharge
Facilities Model, described in Section 5.5, provides the ability to simulate different water inflow
scenarios, different Prado Dam conservation pool elevations and release rates, changes in
basin recharge capacities, and amount of imported water recharged to evaluate the
effectiveness of proposed recharge projects.
In 2014, the District completed a study projecting future Santa Ana River flows. The planning
horizon for this study is approximately 50 years. This work, explained in section 5.5.3, was
done primarily to support work with the U.S. Army Corps of Engineers in studying the feasibility
of increasing the volume of water that can be temporarily impounded behind Prado Dam.
The planning and implementation horizon for water demand projections is dependent upon the
publication of Urban Water Management Plans for cities within the boundaries of OCWD, which
currently have projected demands to 2035.
OCWD Groundwater Management Plan 2015 Update 2-11
BASIN HYDROGEOLOGY
� BM191N BA&N
n ieawahr SaMa Ane River Groundwaler level �
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a�w,�aw�,..�..w.,��a��,aa�a.�,�. ��a�.�,.�^w.w..�a���,�Ua..��.w.v�:u .,�. .:oa,�o�a.o�..,a W�J.+�a,l�.n'.su'�'�rw.& `;�.�mF2oGa�.�rs:,d�,�,�xia` ... � � ..._ .
This section describes the hydrogeology of the Orange County Groundwater
Basin, also refered to as Basin 8-1.
Hydrogeology
• Basin covers approximately 350 square miles in north and central Orange
County
• Basin divided into Forebay and Pressure Areas
• OCWD determined total basin volume
• Water budget incorporates basin inflows and outFlows
Groundwater in Storaqe
• Estimated annually, based on 2007 comprehensive study
• Land subsidence potential monitored
Groundwater Basin Model
• Model encompasses entire basin; updated every 3-5 years
• Talbert Gap model used to assess seawater intrusion
• Alamitos Barrier model constructed in 1965; latest update in 2010
Section 3
Basin Hydrogeology
��CTIO�I 3 BASII� HYDRO���LOGY
�.� DEsc�o�T�o� oF g�s�N HYDRo��oLo��
The Orange County Groundwater Basin is located in the area designated by the California
Department of Water Resources (DWR) as Basin 8-1, the "Coastal Plain of Orange County
Groundwater Basin" in Bulletin 118 (DWR, 2003). Figure 3-1 displays the OCWD boundary in
relation to the boundary of Basin 8-1.
, 'rk��"' `�'�, � �x.�� � ' `` m*Ee����` ry��:
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0 5 10i" ,. '�„� _�...�
�•. o ,� �.�..1 OCWD Boundary
�� �� �_�Counry Boundaries
Figure 3-1: Coastal Plain of Orange County Groundwater Basin, Basin 8-1
OCWD Groundwater Management Plan 2015 Update 3-1
Section 3
Basin Hydrogeology
The basin underlies north and central Orange County beneath broad lowlands known as the
Tustin and Downey plains. The basin covers an area of approximately 350 square miles,
bordered by the Coyote and Chino Hills to the north, the Santa Ana Mountains to the northeast,
and the Pacific Ocean to the southwest. The basin boundary extends to the Orange County-Los
Angeles line to the northwest, where groundwater flow is unrestricted across the county line into
the Central Basin of Los Angeles County. The Newport-Inglewood fault zone forms the
southwestern boundary of all but the Shallow Aquifer in the basin.
The groundwater basin formed in a synclinal, northwest-trending trough that deepens as it
continues beyond the Orange-Los Angeles county line. The Newport-Inglewood fault zone, San
Joaquin Hills, Coyote Hills, and Santa Ana Mountains form the uplifted margins of the syncline.
The total thickness of sedimentary rocks in the basin surpasses 20,000 feet, of which only the
upper 2,000 to 4,000 feet contain fresh water. In the southeastern area underlying the city of
Irvine and along the basin margins, the thickness of fresh water-bearing sediments is less than
1,000 feet (Herndon and Bonsangue, 2006).
Structural folding and faulting along the basin margins, together with down warping and
deposition within the basin, have occurred since Oligocene time. The Newport-Inglewood fault
zone, comprising the most significant structural feature in the basin from a hydrogeologic
standpoint, consists of a series of faulted blocks which are generally up thrown on the
southwest side. Folding and faulting along the Newport-Inglewood fault zone have created a
natural restriction to seawater intrusion into the groundwater basin (Herndon and Bonsangue,
2006).
Pleistocene or younger aquifers within the basin form a complex series of interconnected sand
and gravel deposits. In coastal and central portions of the basin, these deposits are extensively
separated by lower-permeability clay and silt deposits or aquitards. In the inland areas, the clay
and silt deposits become thinner and more discontinuous, allowing larger quantities of
groundwater to flow more easily between shallow and deeper aquifers (California Department of
Water Resources, 1967). Figure 3-2 presents a geologic cross section through the basin along
the Santa Ana River.
OCWD subdivided the groundwater basin into three major aquifer systems, based on geological
data and vertical potentiometric head differences measured regionally at over 50 multi-depth
monitoring wells, shown in Figure 3-8. The three aquifer systems, known as the Shallow,
Principal, and Deep, are hydraulically connected, as groundwater is able to flow between them
via leakage through the intervening aquitards or discontinuities in the aquitards.
The Shallow Aquifer system overlies the entire basin and includes the prolific Talbert Aquifer. It
generally occurs from the surface to approximately 250 feet below ground surface. The majority
of groundwater from the shallow aquifer is pumped by small water systems for industrial and
agricultural use, although the cities of Garden Grove and Newport Beach, and the Yorba Linda
Water District, operate wells that pump from the shallow aquifer for municipal use.
OCWD Groundwater Management Plan 2015 Update 3-2
Section 3
Basin Hydrogeology
Over 90 percent of groundwater production occurs from wells that are screened within the
Principal Aquifer system at depths between 200 and 1,300 feet. A minor amount of
groundwater is pumped from the Deep Aquifer, which underlies the Principal Aquifer system
and is up to 2,000 feet deep in the center of the basin. Hindering production from the Deep
Aquifer system is the depth and the presence of amber colored groundwater in some areas.
The treatment and use of amber colored groundwater is discussed in Section 8.6.
GROUNOWATER F2ECHARGE AREA
HUNTfNGTON FOUNTAIN VAU.EY SANTA ANA ANAHEIM
BEACH BURRIS WARNER �o p" �
Ocean 3eawater SaMa Ana River tiroundwater 1ev�r1 � eaax+ sns�H ����,r4�'0 I'" �
intrusioe ���
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Figure 3-2: Geologic Cross-Section, Orange County Groundwater Basin
3.1 .1 Forebay ar�d Pressure Areas
The Department of Water Resources (DWR, 1934) divided the basin into two primary hydrologic
divisions, the Forebay and Pressure areas, as shown in Figure 3-3. The Forebay/Pressure area
boundary generally delineates the areas where surface water or shallow groundwater can or
cannot move downward to the first producible aquifer in quantities significant from a water
supply perspective. From a water quality perspective, the amount of vertical flow to deeper
aquifers from surface water or shallow groundwater may be significant in terms of impacts of
past agricultural or industrial land uses (e.g., fertilizer application and leaky underground
storage tanks).
The Forebay refers to the area of intake or recharge where most of the groundwater recharge
occurs. Highly-permeable sands and gravels with few and discontinuous clay and silt deposits
allow direct percolation of Santa Ana River and other surface water. The Forebay area
OCWD Groundwater Management Plan 2015 Update 3-3
Section 3
Basin Hydrogeology
encompasses most of the cities of Anaheim, Fullerton, and Villa Park and portions of the cities
of Orange and Yorba Linda.
The Pressure Area is generally defined as the area of the basin where large quantities of
surface water and near-surface groundwater is impeded from percolating into the major
producible aquifers by clay and silt layers at shallow depths (upper 50 feet). The Principal and
Deep Aquifers in this area are under"confined" conditions (under hydrostatic pressure); the
water levels of wells penetrating these aquifers exhibit large seasonal variations. Most of the
central and coastal portions of the basin fall within the Pressure Area.
• La Ha:.. <:�f.,� � � ��' # '�'.�_
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�Feet ��Canfined e�
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Figure 3-3: Orange County Groundwater Basin
OCWD Groundwater Management Plan 2015 Update 3-4
Section 3
Basin Hydrogeology
.3.1 .2 �rc��r�dv�oater Sub�as�ns, Me��s, and Gaps
The Orange County Groundwater Basin, as defined by DWR Bulletin 118 Basin 8-1, can be
subdivided into subbasins and the coastal region can be distinguished by higher and lower
elevation areas, as described in this section and shown in Figure 3-3.
Main Basin
The Main Basin is the largest sub-basin where the majority of groundwater production occurs.
Mesas and Gaps
Four relatively flat elevated areas, known as mesas, occur along the coastal boundary of the
basin. The mesas were formed by ground surface uplift along the Newport Inglewood Fault
Zone. Ancient meandering of the Santa Ana River carved notches through the uplifted area and
left behind sand- and gravel-filled deposits beneath the lowland areas between the mesas,
known as gaps (Poland et al., 1956). Groundwater in the shallow aquifers within the gaps is
susceptible to seawater intrusion. The Talbert and Alamitos seawater intrusion barriers were
constructed to address this problem. Locations of inesas and details of seawater barrier
operations are shown in Figure 7-1.
Irvine Subbasin
The Irvine subbasin, bounded by the Santa Ana Mountains and the San Joaquin Hills, forms the
southern-most portion of the basin. The Costa Mesa Freeway (State Route 55) and Newport
Boulevard form the subbasin's approximate western boundary with the Main Basin. Here, the
aquifers are thinner and contain more clay and silt deposits than aquifers in the main portion of
the basin.
The aquifer base in the Irvine sub-basin ranges from approximately 1,000 feet deep beneath the
former Marine Corps Air Station (MCAS)Tustin to less than 200 feet deep at the eastern
boundary of the former MCAS EI Toro. East of former MCAS EI Toro, the aquifer further thins
and transitions into lower-permeability sandstones and other semi-consolidated sediments,
which have minor water storage and transmission capacity.
Groundwater historically flowed out of the Irvine subbasin westerly into the Main Basin since the
amount of natural recharge in the area, predominantly from the Santa Ana Mountains, was
typically greater than the amount of pumping (Singer, 1973; Banks, 1984). With the operation of
the Irvine Desalter Project commencing in 2007, it is possible that groundwater production in the
Irvine subbasin may exceed the natural replenishment from the adjacent hills and mountains, in
which case groundwater would be drawn into the Irvine subbasin from the Main Basin.
Yorba Linda Subbasin
The Yorba Linda subbasin is located north of the Forebay recharge area in Anaheim, within the
cities of Yorba Linda and Placentia. Due to low transmissivity and high total dissolved solids
(TDS) concentrations (Mills, 1987)there is little groundwater pumped from this subbasin.
Groundwater from the Yorba Linda subbasin flows southward into the Main Basin since the
limited groundwater production is less than the natural replenishment from the adjacent Chino
Hills.
OCWD Groundwater Management Plan 2015 Update 3-5
Section 3
Basin Hydrogeology
�a Habra Subbasin
The La Habra subbasin is located north of the Main Basin within the cities of La Habra and
Brea. It comprises a shallow alluvial depression between the Coyote Hills and the Puente Hills.
Prior to the 1950s, hundreds of wells produced water for domestic use and irrigation. The
majority of these wells were abandoned due to high concentrations of nitrate, total dissolved
solids, and metals and taste and odor problems. However, in recent years, the City of La Habra
has explored options to increase groundwater production from this subbasin.
Hydrogeologic studies have indicated that 2,200 to 5,500 afy of groundwater flows out of the La
Habra Basin in finro areas: (1) southerly into the Main Basin along the Brea Creek drainage
between the East and West Coyote Hills and (2)westerly into the Central Basin in Los Angeles
County (James M. Montgomery, 1977; Ramsey, 1980; OCWD, 1994). The areas that lie outside
the District boundaries in the northern portion of Basin 8-1, as defined in DWR Bulletin 118, are
located in the La Habra subbasin.
3.1 .3 �a�stal Plair� of Orang� Gc��ar�ty; Ar�as outsid� {��V1/D Bc��ndari�s
The District boundaries do not encompass the entire area of Basin 8-1 as defined by DWR as
shown in Figure 3-4. Areas that are outside of OCWD's boundary are shown in red highlight.
These areas include (1) a northern portion of DWR Basin 8-1 located in the La Habra subbasin,
a portion of which is in Los Angeles County, (2) areas along the mountain fronts at the eastern
side of the basin and in the southern portion of Basin 8-1 within the Irvine subbasin, and (3) a
portion of Basin 8-1 immediately downstream of Prado Dam located in Riverside and San
Bernardino counties. None of the areas that are included in Basin 8-1 outside of OCWD
boundaries are within the boundaries of other sustainability agencies and have not as yet been
incorporated into a groundwater management plan or a groundwater sustainability plan. OCWD
is coordinating with the City of La Habra, the County of Orange, Irvine Ranch Water District, and
other stakeholders regarding management of these areas outside the OCWD boundary.
3.2 DET�RM! ,�0�10(� (�F YC7TAL BA�SIi� �f{�L.UN1E
A vast amount of fresh water is stored within the basin, although only a fraction of this water can
be removed practically using pumping wells and without causing physical damage such as
seawater intrusion or the potential for land subsidence (Alley, 2006). Nonetheless, it is
important to note the total volume of groundwater that is within the active flow system, i.e.,
within the influence of pumping and recharge operations.
OCWD used its geographic information system and the aquifer system boundaries described in
Section 3.8 to calculate the total volume of each of the three major aquifer systems as well as
the intervening aquitards. The total volume was calculated by multiplying the area and
thickness of each hydrogeologic unit. Because groundwater fills the pore spaces that represent
typically between 20 and 30 percent of the total volume, the total volume was multiplied by this
porosity percentage to arrive at a total groundwater volume. Assuming the basin is completely
full, based on District estimates, the total amount of fresh groundwater stored in the basin is
approximately 66 million acre-feet, as shown in Table 3-1.
OCWD Groundwater Management Plan 2015 Update 3-6
Section 3
Basin Hydrogeology
For comparison, DWR (1967) estimated that about 38 million acre-feet of fresh water is stored
in the groundwater basin when full. DWR used a factor known as the specific yield to calculate
this volume. The specific yield (typically between 10 and 20 percent) is the amount of water that
can be drained by gravity from a certain volume of aquifer and reflects the soil's ability to retain
and hold a significant volume of water due to capillary effects. Thus, DWR's drainable
groundwater volume can be considered consistent with OCWD's estimate of tota/groundwater
volume in the basin.
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Figure 3-4: Basin 8-1 and OCWD Boundaries
OCWD Groundwater Management Plan 2015 Update 3-7
Section 3
Basin Hydrogeology
Table 3-1: Estimated Basin Groundwater Storage by Hydrogeologic Unit
(Volumes in Acre-feet)
HYDROGEOLOGIC UNIT PRESSURE AREA FOREBAY TOTAL
Shallow Aq�if�€-System �,BQ�i,000 1,2�0,00� S,OOtl,000
Aquitard 9{?fl,OQO 200,000 �,100,��(�
Prjn�ipal Aqc�ifer Systerr� 24,300,00� 8,6aQ,000 32,9D0,00�
A,quitard 1,6flQ,OQfl 3Q0,000 1,900,000
Deep Aquif�r Syst�m 18,8flCl,000 6,30t1,00�1 25,fi�?C?,(l00
TflTfi�. 49,4Q0;000 16,600,000 66,OQfl,000
Notes: (1)Volumes calculated using the 3-layer basin model surfaces with Arclnfo Workstation GRID. (2)A
porosity of 0.25 was assumed for aquifer systems. (3)A porosity of 0.30 was assumed for aquitards.
�.� �AT�R BUd��T
OCWD developed a hydrologic budget (inflows and outflows)for the purpose of constructing the
basin-wide groundwater flow model, ("Basin Model") and for evaluating basin production
capacity and recharge requirements. The key components of the budget include measured and
unmeasured (estimated) recharge, groundwater production, and subsurface flows along the
coast and across the Orange County/Los Angeles County line. Because the basin is not
operated on an annual safe-yield basis, the net change in storage in any given year may be
positive or negative; however, over a period of several years, the basin must be maintained in
an approximate balance as explained in Section 10.
Table 3-2 presents the components of an example balanced basin water budget (no annual
change in storage). Note that it does not represent data for any particular year. The annual
budget presented is based on the following assumptions: (1) average precipitation, (2) basin
storage at 400,000 acre-feet below full, (3) recharge of 274,500 acre-feet in District facilities
including surface spreading basins and seawater intrusion bar�ier wells, and (4) adjusted
groundwater production so that total basin inflows and outflows are equal. The sources of
recharge water used by the District include Santa Ana River base flow and storm flow, imported
water, and GWRS recycled water. The major components of the water budget are described in
the following sections.
3.3.1 Measured Recharge
Measured recharge consists of all water artificially recharged at OCWD's surFace water
recharge facilities and water injected in the Talbert and Alamitos Barriers. The majority of
measured recharge occurs in the District's surFace water system, which receives Santa Ana
River base flow and storm flow, imported water and GWRS recycled water. The importance of
OCWD Groundwater Management Plan 2015 Update 3-8
Section 3
Basin Hydrogeology
these sources has changed over time, as shown in Figure 5-8. In recent years, GWRS and
imported water have become more important as the volume of Santa Ana River base flow
declines.
OCWD's Talbert Barrier is a series of injection wells that span the 2.5-mile wide Talbert Gap,
between the Newport and Huntington Beach mesas. Purified water produced by the GWRS is
injected into multiple aquifers; over 95 percent of the injected water flows inland and becomes
part of the basin's groundwater supply.
The Alamitos Barrier is a series of wells injecting a blend of imported and recycled water into
multiple aquifer zones that span the Alamitos Gap at the Los Angeles/Orange County line.
Essentially all of the injected water flows inland, replenishing groundwater basins in the two
counties. Inspection of groundwater contour maps indicates that roughly one-third of the
Alamitos Barrier injection water remains within or flows into Orange County.
Table 3-2: Example Annual Basin Water Budget
FLOW COMPONENT Acre-feet per Year
3�3F�OV�d
Me�sured Rech�rge
1. Surfa�e rech�rge f���liti�s' 243,000
2. Talber� Barrier inject6cs� 30,Ot�fl
3. Alarnitr�s Barrier i�j�cticar�, Orang� C;�a�traty pca�tion onEy 2,000
Subtc�tal: 275,t�#DO
Estirrrated Unmeasured c�r I��id�nt�l Rect�arge�
1. Sub�urfa�e Inf{c�w 47,a��
2. Rre�1 r�charge frorr� rair�falilirrigati�n 1�,000
Sub�c�ta1; 66,fl00
TOTAL INFLOW: 341,000
t�UTFLC9V11
1, Groundvrrat�r Prcad��t��ra 335,0�0
2. ��absurf��e �utf3ov+r 6,OU0
TOTAL OUTFLOW: 341,000
CHANGE IN STORAGE: 0
' Evaporation from surface recharge facilities is estimated to be 2,000 afy.
2 Assuming average precipitation (14 inches/year)
OCWD Groundwater Management Plan 2015 Update 3-9
Section 3
Basin Hydrogeology
3.3.2 Unmeasured Rech�r�e
Unmeasured recharge also referred to as "incidental recharge" accounts for a significant
amount of the basin's sustainable yield. This includes recharge from precipitation, irrigation
return flows, urban runoff, seawater inflow through the gaps as well as subsurface inflow at the
basin margins along the Chino, Coyote, and San Joaquin Hills and the Santa Ana Mountains
and beneath the Santa Ana River and Santiago Creek. Subsurface inflow in the Santa Ana
River and Santiago Creek refers to groundwater that enters the basin at the mouth of Santa Ana
Canyon and in the Santiago Creek drainage below Villa Park Dam. Estimated average
subsurface inflow to the basin is shown in Figure 3-5.
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Dwinaae ioto OCWD Basin AFY �.� ,�� �� �'�°'�;�'
1.Inflow from LaH�ra trasin 3,000 �� ' �' ,,„,` � �`,-�� �'
2 Recharge from foothills into � '"�"" � - ,� r' �� "�� ��
Irvine subbasin 14,Q00 ��t���
. �� + '� {"Tt� �� t� f,
f
3.Recharge from foolhills into ��, ,,, �� ���r�' � ���,�,�' �y�,°��� �
Yorba Linda subbasin 6,000 ,xf �� �f � ��'� � �- �'��, .fi•�� ���,��`�t
4.Subsurface inflow at Imperial � '� � ���a � �' ����€
Hwy beneath the SAR d,000 ••,,.�''''� `� � � ��"`" ���� � �� ' �,�,�
5.Subsu�face inflow f�om �� ' � +� g�� � '�� �� �.� �
San6ago Canyon 10.000 � � i ¢''� � �� `��`� �°���s� � :
6.Recharge along Peralta Hills 4,000 " ' ..,,,, � � p r�� � � � � �
7 Recha�ge along Tustin Hills 6,000 � ""w.... i� ` �^' � � � " �
�, ,, o �.oao ,..aa7 '`e,! � �� °`✓��
nam.,,zc;nacwncv.uataaers 4/�� �oF� � '.{ �, "��a � '� xt
f".� . ,.. �;�' °'�' ��e:.
Figure 3-5: Estimated Subsurface Recharge
Total unmeasured recharge ranges between 20,000 to 160,000 afy. This number is the volume
left over after all the basin inputs and outputs are accounted for. Net unmeasured or incidental
recharge is the amount of incidental recharge remaining in the basin after accounting for losses
to Los Angeles County. Under average hydrologic conditions, net incidental recharge averages
66,000 acre-feet per year. This average was substantiated during calibration of the Basin
OCWD Groundwater Management Plan 2015 Update 3-10
Section 3
Basin Hydrogeology
Model and is also consistent with the estimate of 58,000 afy reported by Hardt and Cordes
(1971) as part of a U.S. Geological Survey (USGS) modeling study of the basin. Because
unmeasured recharge is one of the least understood components of the basin's water budget,
the error margin for any given year is probably in the range of 10,000 to 20,000 acre-feet. Since
unmeasured recharge is well distributed throughout the basin, the physical significance
(e.g., water level drawdown or mounding in any given area) of over-or underestimating the total
recharge volume within this error margin is considered to be minor.
3.3.3 Grc�und�vater Produ�tiQr�
Active wells pumping water from the basin are shown in Figure 3-6. The approximately 200 large-
system wells account for an estimated 97 percent of the total basin production; 200 small
production wells
�,. ��..;� .���-�,��-_ � ���..� �,�¢_��� produce less than
< r°'� �'�,��` .�,,�,�� �`-��,�r � ,�����,.. 25 afy. Large-
�� �� , �
� ��'� �- - -�-�. �� � 3 " �"" � capacity wells are
. �: ��:>,f ,�
� , ���� �`���� � ��� all metered, as
,. _� , .� �<., �� r
�'r��� ' � required by the
,� �� � ,,w ;� �F;.,.� �,�`�' District Act.
�
�- �x`� r ���"'� � `'° Production data
�� ��.� � �� :.� ��� .
~���`�� � ;�-" '�;��`� ����� �� � � � was recorded on
� �. �"'� �� �� � � �;� �
� � Q _
. � ��
�. r �a_� � ,/) ` ��1 � �� �; °�►��`� ���� �� a semi-annual
w ra` f �
[� .. � � Y•-`�'� ��
._ R ' .w
� ✓ - � �,�x`�� - � �` �„� basin until 1988
-,3 _ � t ��. � <'� �; �,�'` �;i
; , � �, �.� �,� � ,a when the District
' g � �� �`��` � :��,�� � i� began obtaining
. � , >
,
.. �
- . _-
.. t �
�.,; � �' R, � £��,v � ;'Y`� .� monthly individual
� �
,�
�
�'''. � �:_ 0 �» #�a ., ���� ;�.`� well production
r, _ ���.� �.9�ro..
,,�•'' ,�•- �f' measurements.
,d
�,,, � .
' " ••, �
`�., � : �� � a �,
� �,
'•,, � t £ ,r,� �
,=
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„��„�;
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�t �'� x . � j" .�` x� t`x ,�"
� 3
��'4 � � . '. �, s . �� # �I + �!'�'`:�a
,� � i
'..y !y . P�� w" �t f '�'�' i
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'F + �
�''�.� �s � � , .�� `� � �;�� �`
� ''`. ,}�'� ��"� ��`��` � � �.,�� � ��°������ '
N �'"�c� '�_��- � Productbn Wall Lxatbn }
^�^,� and Volume{acre-teet)
1M � E *� � �°-� J"� � t' � July 2013 through June 2014 �
� L^+,,,� � `'��v --8.OU0 Size of ckcle �
� •..,,�, � �" �` � - 3,000 iy proportbnal �
0 10.0a0 Z0.000 �t`� ���;�� � '� �"�`_-300 4o volume
�FOCt 1.�,.1�+{N�BOUt1C�8fy
�:r� <., .... a*�:a., . , .a.,ro:
Figure 3-6: Distribution of Groundwater Production, Water Year 2013-14
OCWD Groundwater Management Plan 2015 Update 3-11
Section 3
Basin Hydrogeology
3.3.4 SubsurFace Outflow
Groundwater outflow from the basin across the Los Angeles/Orange County line has been
estimated to range from approximately 1,000 to 14,000 afy based on groundwater elevation
gradients and aquifer transmissivity (DWR, 1967; McGillicuddy, 1989). The Water Replenishment
District of Southern California also has estimated underflow from Orange County to Los Angeles
County within the aforementioned range.
Modeling by OCWD indicates that assuming that groundwater elevations in Los Angeles County
remain constant underflow to Los Angeles County increases by approximately 7,500 afy for
every 100,000 acre-feet of increased groundwater in storage in Orange County (see Figure 3-
7). With the exception of unknown amounts of semi-perched (near-surFace) groundwater being
intercepted and drained by submerged sewer trunk lines and unlined flood control channels
along coastal portions of the basin, no other significant basin outflows are known to occur.
Simulated outflow to LA County, acre-feet/year
40,000
30,000 � �� -----
20,000 _ June 2014
� � 342,000 acre-
feet below full
condition
� 10,000 � --------- __._ _..__ �,_ ____-- -------
Outflow to LA '
0
Inflow from LA
-10,000
0 100,000 200,000 300,000 400,000 500,000
Available Storage Space (amount below full condition), acre-feet
Figure 3-7: Relationship between OCWD Basin Storage and
Estimated Outflow to Los Angeles County
3.3.5 Ev�poratian
The total wetted area of the District's recharge system is over 1,000 acres. OCWD estimates
the evaporation from this system on a monthly basis. Generally, total evaporation is on the
OCWD Groundwater Management Plan 2015 Update 3-12
Section 3
Basin Hydrogeology
order of 2,000 acre-feet per year which is approximately one percent of the total volume
recharged annually. The relatively minor impact of evaporation reflects high percolation rates (1
to 10 feet per day).
3.4 �ALCULATIU�1 t�F' +��-IAI�GE IN �RC�4J�l�WATER STORAGE
Even though the groundwater basin contains an estimated 66 million acre-feet when full, OCWD
operates the basin from a full condition to approximately 500,000 acre-feet below full to protect
against irreversible seawater intrusion and land subsidence. On a short-term basis, the basin
can be operated at an even lower storage level in an emergency.
The District manages storage and water levels in the groundwater basin within a safe operating
range as described in Section 10. The safe operating range is defined as the upper and lower
levels of groundwater storage in the basin that can be reached without causing negative or
adverse impacts. In order to manage the basin within this safe operating range, OCWD
calculates the amount of groundwater in storage on an annual basis.
The estimated historical minimum storage level of 500,000 to 700,000 acre-feet below full
condition occurred in 1956-57 (DWR, 1967; OCWD, 2003). Since this time, the basin storage
fluctuated within the safe operating range reaching a full condition in 1969, and 1983. Even
though the District calculates and reports accumulated overdraft in its annual Engineers Report,
"overdraft" in the traditional sense does not exist in the Orange County Groundwater Basin
because the basin is operated to continuously fluctuate within the safe operating range.
The District uses finro methods to calculate the storage condition of the basin: (1)water budget
method and (2)three-layer storage change method.
The water budget method is simply an accounting of the inflows to the basin and outFlows. This
data is collected and compiled on a monthly basis. Estimates of unmeasured or incidental
recharge are used until trued up at the end of the year with the final reports of inflows and
outflows. This method produces a monthly estimate of the change in groundwater storage and
allows for virtually real-time decision making with respect to managing the basin.
In 2007, OCWD instituted a new three-layer change in storage method for calculating the
amount of groundwater in storage. The three-layer method involves creating groundwater
elevation contour maps for each of the three aquifer layers (Shallow, Principal, and Deep
Aquifers) in the basin, schematically represented in Figure 3-8, for conditions at the end of June
of each year.
The need for this method was driven by the record-setting wet year of 2004-05, in which water
levels throughout the basin approached a near-full condition. An analysis of the amount of
groundwater in storage compared to the estimate using a one-layer change in storage method
showed a discrepancy of 150,000 acre-feet. The discrepancy of 150,000 acre-feet in two
different calculations indicated that the current condition could not be properly rectified back to
the prior 1969 benchmark. This brought to light three important discoveries:
OCWD Groundwater Management Plan 2015 Update 3-13
Section 3
Basin Hydrogeology
• The one-layer storage change calculation contained considerable uncertainty that when
cumulatively added over tens of years led to a large discrepancy in the level of water in
storage relative to 1969.
• Water level conditions in 1969 no longer represented a full basin, particularly because of
change in pumping and recharge conditions.
• A more accurate storage change calculation should be based on water level changes
and storage coefficients for each of the three major aquifer systems.
In February 2007, the District adopted an updated approach to defining the full basin condition
and calculating storage changes. This updated approach includes:
• A new full-basin groundwater level based on the following prescribed conditions:
o Observed historical high water levels
o Present-day pumping and recharge conditions
o Protection from seawater intrusion
o Minimal potential for mounding at or near recharge basins
• Calculation of the amount of groundwater in storage in each of the three major aquifer
systems.
A more detailed description of the three-layer methodology is presented in OCWD's Report
on Eva/uation of Orange County Groundwater Basin Storage and Operational Strategy
(February 2007) and can be found in Appendix D.
HUNTINGTON SANTA ANA ANpHE1M
Pacific BEACH �
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Figure 3-8: Schematic Cross-Section of the Basin Showing Three Aquifer Layers
OCWD Groundwater Management Plan 2015 Update 3-14
Section 3
Basin Hydrogeology
Figure 3-9 shows the contoured water levels for the Principal Aquifer in June 2014. The maps
are prepared annually and scanned and digitized into the DistricYs GIS database. The previous
year's water levels are subtracted from the current water levels to calculate change in water
levels. Water level change contour maps are prepared for each of the three aquifer layers.
Figure 3-10 shows the water level change for the Principal Aquifer from June 2013 to June
2014. For each of the three aquifers, the GIS is used to multiply the water level changes by a
grid of aquifer storage coefficients from OCWD's calibrated groundwater flow model. This
results in a storage change volume for each of the three aquifers which are totaled to provide a
net annual storage change for the basin, shown in Figure 3-11. In cases where there is a
calculation discrepancy between the storage changes estimated by the two methods, the
unmeasured recharge value is adjusted to eliminate the difference.
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Vmlleal Datun NOVD 28
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Figure 3-9: Groundwater Level Contour Map, June 2014
OCWD Groundwater Management Plan 2015 Update 3-15
Section 3
Basin Hydrogeology
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• q , a y
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��°� ��r. I.����?'"�:��� s'� �:� �,.�- .
Figure 3-10: Groundwater Level Changes, June 2013-14
OCWD Groundwater Management P1an 2015 Update 3-16
Section 3
Basin Hydrogeology
o _
Available
Storage Space 50 4�
(amount below �°x
full condition) 100 � ,
Acre-feet(x1000) 150 � �f„
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1974-75 1978-79 1982-83 1986-87 1990-91 1994-95 1998-99 2002-03 2006-07 2010-11 2014-15
Water Year
Figure 3-11: Change in Groundwater Storage, WY 1974-75 to
2013-14
3.5 ELEIIATIflN TRENDS
The groundwater elevation profile for the Principal Aquifer following the Santa Ana River from
the ocean to the Forebay in Anaheim, for 1969, 2013, and the theoretical full condition are
shown in Figure 3-12. A comparison of these profiles shows that groundwater elevations in the
Forebay recharge area for all three conditions are similar while in the central and coastal areas
of the basin elevations in 2013 are significantly lower. The lowering of coastal area groundwater
levels relative to groundwater levels further inland in the Forebay translates into a steeper
hydraulic gradient, which drives greater flow from the Forebay to the coastal areas. However,
the lowering of coastal water levels also increases the risk of seawater intrusion.
Groundwater elevation trends can be examined using five wells with long-term groundwater
level data, the locations of which are shown in Figure 3-13. Figures 3-14 and 3-15 show water
level hydrographs for wells SA-21 and GG-16, representing historical conditions in the Pressure
area and well A-27, representing historical conditions in the Forebay. Water level data for well
A-27 near Anaheim Lake dates back to 1932 and indicate that the historic low water level in this
area occurred in 1951-52. The subsequent replenishment of Colorado River water essentially
refilled the basin by 1965. Water levels in this well reached an historic high in 1994 and have
generally remained high as recharge has been nearly continuous at Anaheim Lake since the
late 1950s.
OCWD Groundwater Management Plan 2015 Update 3-17
Section 3
Basin Hydrogeology
Elevation (feet MSL)
soa
COSTA MESA ANAHEIM
250 ,. ,.-'^
GROUND SURFACE �' .'f
200 ------- FULLBASIN(THEORETICAL) '� "r
J ,.'/
-—-— 1969(NEAR FULL BASIN) ; �
150 2013(242,000 AF BELOW FULL) ��
i
. •
10Q ,--- ��� fi
_ .r`
,' -,'
, �.,,..
SU ' -.--
�, �,,�.,�,.''.,-
p ��—•'"'_:��=~� ___ MEAN SEA LEVEL
-50
-1 OO pRESSURE AREA�FOREBAY
-150
2 4 6 8 10 12 14 16 18 20
MILES FROM COAST ALONG SANTA ANA RIVER
Figure 3-12: Principal Aquifer Groundwater Elevation Profiles, 1969 and 2013
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8 ""'"^.., � �"�.w^�� �' Rk7s�toring WbN �
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�iest � . ���� 4.....i�WDBou�fary
..o .. .. ..*..,, r . ,�...
Figure 3-13: Location of Long-Term Groundwater Elevation Hydrograph -
OCWD Groundwater Management Plan 2015 Update 3-18
Section 3
Basin Hydrogeology
SA-21 WATER LEVELS
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Figure 3-14: Water Level Hydrographs of Wells SA-21 and GG-16 in Pressure Area
OCWD Groundwater Management Plan 2015 Update 3-19
Section 3
Basin Hydrogeology
��
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Figure 3-15: Water Level Hydrographs of Well A-27 in Forebay
The hydrograph for well SA-21 indicates that water levels in this area have decreased since
1970. Also noteworthy is the large range of water level fluctuations from the early 1990s to
early 2000s. The increased water level fluctuations during this period were due to a
combination seasonal water demand-driven pumping and participation in the MWD Short-Term
Seasonal Storage Program by local Producers (Boyle Engineering and OCWD, 1997), which
encouraged increased pumping from the groundwater basin during summer months when MWD
was experiencing high demand for imported water. Although this program did not increase the
amount of pumping from the basin on an annual basis, it did result in greater water level
declines during the summer during the period of 1989 to 2002 when the program was active.
Figure 3-16 presents water level hydrographs of two OCWD multi-depth monitoring wells, SAR-
1 and OCWD-CTG1, showing the relationship between water level elevations in aquifer zones
at different depths. The hydrograph of well SAR-1 in the Forebay exhibits a similarity in water
levels between shallow and deep aquifers, which indicates the high degree of hydraulic
interconnection between aquifers characteristic of much of the Forebay.
The hydrograph of well OCWD-CTG1 is typical of the Pressure Area in that there are large
differences in water levels in different aquifers, indicating a reduced level of hydraulic
interconnectivity between shallow and deep aquifers caused by fine-grained layers that restrict
vertical groundwater flow. Water levels in the deepest aquifer zone at well OCWD-CTG1 are
higher than overlying aquifers, in part, because few wells directly produce water from these
zones. The lack of production from the deepest aquifers is due to the presences of amber-
colored water and the depth required to produce water from these zones.
OCWD Groundwater Management Plan 2015 Update 3-20
Section 3
Basin Hydrogeology
SAR-1 WATER LEVELS
120 R.P.Elevation: 210.09 feet msl
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OCWD-CTG1 Water Levels
40
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�---�OCWD-CTGAIS RP Elev-32.80 fl msl;PeA InL 160-260 R bgs
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p ______________......._'..�_"'___.'_;_._._._ w._..._...�QCWD-CTG1l3RPElev-32.82flms�l Perfint800-1p'15ttbys .._-.....
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�' ' " � NOTE: Ve�M1iwl scate grqaier than scafe used fur other MuNi-depthj waq graphs.
-144
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Figure 3-16: Water Level Hydrographs of Wells SAR-1 and OCWD-CTG1
OCWD Groundwater Management Plan 2015 Update 3-21
Section 3
Basin Hydrogeology
3.6 LAND SUBS9DE�1�E
Land subsidence can be caused by a number of factors, including collapse of underground
cavities, tectonic activity, natural consolidation of sediment, oxidation of organic deposits,
hydrocompaction of moisture-deficient soil and sediments, development of geothermal energy,
extraction of hydrocarbons from the subsurface, and extraction of groundwater.
In California, a common cause of subsidence is associated with excessive groundwater
withdrawals. In the case of thick sedimentary groundwater basins comprised of alternating
"confined" or"pressure" aquifers (permeable sands and gravels) and aquitards (less permeable
silts and clays), the extraction of groundwater reduces the fluid pressure of the saturated pore
spaces within the buried sediments. The pressure reduction in the deeper sediments allows the
weight of the overlying sediments to compact the deeper sediments, particularly the clays and
silts. If groundwater withdrawals cause water levels to be sustained beyond historical lows,
several years or more, the incremental amount of sediment compaction can eventually manifest
itself in an irreversible permanent lowering of the land surface (USGS, 1999).
In Orange County, subsidence in swampy low-lying coastal areas underlain by shallow organic
peat deposits started as early as 1898 when development of these areas for agriculture resulted
in excavation of unlined drainage ditches. The drainage ditches drained the swamps and
intercepted the shallow water table which was lowered sufficiently to allow the land to drain
adequately for irrigated agriculture. When the shallow water table was lowered, it exposed the
formerly-saturated peat deposits to oxygen that caused depletion and shrinkage of the peat due
to oxidation (Fairchild and Wiebe, 1976). Subsidence of shallow peat deposits was associated
with land development practices that occurred in Orange County in the late 1800s and early
1900s and, as such, is not something associated with or controlled by groundwater withdrawals
in the basin. Another documented cause of subsidence in Orange County unrelated to
groundwater basin utilization is oil extraction along the coast, particularly in Huntington Beach
(Morton et. al, 1978).
Subsidence due to changes in groundwater conditions in the Orange County groundwater basin
is variable and does not show a pattern of widespread irreversible permanent lowering of the
ground surface. Storage conditions in the groundwater basin were at historical lows in the late
1950s, but since this time OCWD has operated the groundwater basin within a storage range
above the historical low. There are reports that some subsidence may have occurred before
OCWD began refilling the groundwater basin in the late 1950s (Morton, et al., 1976); however,
the magnitude and scope of this subsidence is uncertain and it is not clear if this subsidence
was permanent.
More recent data show a consistent pattern of the ground surface rising and falling in tandem
with groundwater levels and overall changes in basin groundwater storage. This is referred to
as elastic subsidence. Interferometric Synthetic Aperture Radar(InSAR) data collected from
satellites and data collected by the Orange County Surveyor(Surveyor) show that ground
surface elevations in Orange County both rise and fall in response to groundwater recharge and
withdrawals. InSAR data during the period 1993-1999 shows temporary seasonal land surface
OCWD Groundwater Management Plan 2015 Update 3-22
Section 3
Basin Hydrogeology
changes of up to 4.3 inches (total seasonal amplitude from high to low) in the Los Angeles-
Orange County area and a net decline of approximately 0.5 inch/year near Santa Ana over the
period 1993 to 1999, which happened to coincide with a period of net withdrawal of groundwater
from the basin (Bawden, 2001; 2003).
The Surveyor's office maintains more than 1,500 elevation benchmarks throughout Orange
County. Periodically, the Surveyor resurveys the benchmarks to detect changes in elevation.
The Surveyor maintains the survey records and makes them available to the public
(http://ocpublicworks.com/survey/services/ocrtn)and provides the data to OCWD upon request.
The Surveyor also maintains an Orange County Real Time Network (OCRTN)that consists of
continuously operating GPS reference stations that monitor horizontal and vertical movement
throughout Orange County. Figure 3-17 shows the locations of the GPS stations in Orange
County.
Based on real time GPS data, the BLSA and SACY sites show the greatest range of elevation
change of any of the sites in Orange County. Ground surface elevation changes at these sites
from 2002 to 2014 correlate well with changes in groundwater storage, as shown on Figure 3-
18. Note that this period of
time includes a very wet . �
period (2004-05)when basin ,�, � ,;�,�,�,g,�n ��,,,� �N ,- '- �
groundwater storage � _ ��,�,��b �����.
� �___._v.______ ._ _.�
, �
increased significantly and a ,���, , E ;�SN+YS '`-,�� ��,Y
dry period (2010-2014)when � �,� �' `w.�
basin groundwater storage �� �' �cC�� `�� �
decreased significantly. �" �'��
'`� BLSA �,, ��cuae
In reviewing the available ,�f �, ���
sources of data, it is clear � DEpC ',�,,
that depending on the time � �SACY �' �---�
period selected, the ground �� �� �.� AA.}PK� � �� �a�`
surface is rising, falling, or �,� W--�,�
remaining stable. GPS data fl''�'�� �` `��
collected by the Surveyor TRAK
over the past 12 years "� ,F'f
(2002-14) show that the �`
f
ground surface fluctuations ��s�C �4�r��.
appear to be completely ��� �'
elastic, reversible, and well ;' -- ---
correlated with fluctuations in ��� �� �i
groundwater levels. These fl ;f`�y��
,
data indicate that there has ' ' �' �'
not been any permanent, ���'�������'������'��`��`�` `�'l�i� t� o��co
C�Cf��'N-�G�'�1�}4L TthiE NE�Y�,+'G'RK couivrr
irreversible subsidence of � _R�rir�E��r���r�r���
the ground surface over the
past 12 years.
Figure 3-17: Orange County Public Works GPS Real Time Network
OCWD Groundwater Management Pian 2015 Update 3-23
Section 3
Basin Hydrogeology
Finally, there is little potential for future widespread permanent, irreversible subsidence given
OCWD's statutory commitment to sustainable groundwater management and policy of
maintaining groundwater storage levels within a specified operating range. Nevertheless, the
District annually reviews Surveyor data to evaluate ground surface fluctuations within the
District's service area. If irreversible subsidence was found to occur in a localized area in
relation to groundwater pumping patterns or groundwater storage conditions, OCWD would
coordinate with local officials to investigate and develop an approach to address the
subsidence.
N m 4 ut w n 00 m o .� ry r�*f V•
0 0 0 o a o 0 0 ,1 .-i r+ .� r+
v w tii ai v w v u w ai aa ai w
C C C C C C C c C c C C C
7 7 7 7 � 7 7 7 7 7 7 7 7
� � -. � � --� � � � � -� � � �
Available Storage Space �„����g�,�
—_._ _____--- ---------- — aoa,oaa
w
a�
.___------_.___ .�_....__.________ __.._._.__.______.._._...__..____...__......._----------____...__.._ _,�---__.__ zao,aQo �'
a�
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U
Q
---�--- -------- — -- — - $00,{1Q0
4�O,a0Q
z:a ..______ ------------------------------ ---
Ground Surface Elevation Change
Q
�.a ..___ __._.______..------------...._._._.__..._._..________________---------- -._____.�_____________._.__._._. �_'�.----.____.._____
c� _ ,;
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_._ __.-- -- .-------- -. _._._.____.�-----_
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-a.o _�.�._�._----
-z.o
-#-BL'SA Change in Elevation{in� -��°-S/�CY Changre in Etevativn�in} ••E•.Groundwater Stor�tge
Figure 3-18: Available Storage Space in the Orange County Groundwater Basin and
Ground Surface Elevation Change, 2002-2014
OCWD Groundwater Management Plan 2015 Update 3-24
Section 3
Basin Hydrogeology
3.7� BA�1N fV90DEL
OCWD's basin model encompasses the entire basin and extends approximately three miles into
the Central Basin in Los Angeles County to provide for more accurate model results than if the
model boundary stopped at the county line (see Figure 3-19). As noted previously in this
chapter, the county line is not a hydrogeologic boundary, i.e., groundwater freely flows through
aquifers that have been correlated across the county line.
Coverage of the modeled area is accomplished with grid cells having horizontal dimensions of
��`�'� �`"`�...,.�`�
�,��.,•� -�-� • � � � �r��, � 500 feet by 500 feet
—., r � ����R� �� ,$, , ���� (approximately 5.7
--- '� ,- acres) and vertical
e7�°' d
Central '"�'� �' "'� � � .:�� ���� dimensions ranging
�� �� �
Basin <� , 4 , � ��.
�, �., t� �, � � from approximately 50
� , �.. -;��'.�,
��' to 1,800 feet,
�
r'"` � �;`��,, ��;� depending on the
�� �,� 3��� �� r thickness of each
�,,.
��'� '"�' model layer at that
°`
Oranae Counri '`�p �- grid cell location.
Oroundwater Basin
��� � ������ Basin aquifers and
� ��,� r ����,y�"� aquitards are grouped
' ��°°� into three composite
� t�'� �L
� �
'�"`�.. q '� A' ,��� �'�� model layers thought
x � ,� �;. :;
.d`� a �'15;,�
.�� �� ., � "��- �� sufficient to describe
�,�� � the three
```�: �x:��� � distinguishable flow
, ,
'� ��, ;: systems
,`••� ��° ��� � ' �`t� corresponding to the
.� �� ;�
� _ ` " � ` '' Shallow, Principal, and
•`�,� �� � ;�,�t ��, ,�; ..
� c
H �"`� � � �-�� � ,�a ��. Deep Aquifers. The
r �'
� , � E ��`•�,,,,�� � ���°`,�r ,�� � .,,�s�� ����b. ���� " three model layers
��'�r���� �
�`e� � �� � p�Ye�,�s�aa�,, �; comprise a network of
s . `�� � .�
�Layer 2(Pnrtcipap �
° �°•000 zo.000 "�+`.',^»�.,,�, it a�` ,:� Qtayaratoeep> OV@P 90,��0 g�IC� C@��S.
�Feet •..��� ,� r`OCWD 8ounda
t.. .i ry
Figure 3-19: Basin Model Extent l f � ~L
The widely-accepted computer program, "MODFLOW," developed by the USGS, was used as
the base modeling code for the mathematical model (McDonald and Harbaugh, 1988).
Analogous to an off-the-shelf spreadsheet program needing data to be functional, MODFLOW
requires vast amounts of input data to define the hydrogeologic conditions in the conceptual
model. The types of information that must be input in digital format (data files)for each grid cell
in each model layer include the following:
• Aquifer top and bottom elevations
OCWD Groundwater Management Plan 2015 Update 3-25
Section 3
Basin Hydrogeology
• Aquifer lateral boundary conditions (ocean, faults, mountains)
• Aquifer hydraulic conductivity and storage coefficient/specific yield
• Initial groundwater surFace elevation
• Natural and artificial recharge rates (runoff, precipitation, percolation, injection)
• Groundwater production rates for approximately 200 large system and 200 small system
wells
These data originate from hand-drawn contour maps, spreadsheets, and the Water Resources
Management System (WRMS) historical database. Because MODFLOW requires the input
data files in a specific format, staff developed a customized database and GIS program to
automate data compilation and formatting functions. These data pre-processing tasks form one
of the key activities in the model development process.
Before a groundwater model can be reliably used as a predictive tool for simulating future
conditions, the model must be calibrated to reach an acceptable match between simulated and
actual observed conditions. The basin model was first calibrated to steady-state conditions to
numerically stabilize the simulations, to make rough adjustments to the water budget terms, and
to generally match regional groundwater flow patterns. Also, the steady-state calibration helped
to determine the sensitivity of simulated groundwater levels to changes in incidental recharge
and aquifer parameters such as hydraulic conductivity. Steady-state calibration of the basin
model is documented in more detail in the OCWD Master P/an Report(OCWD, 1999).
Typical transient model output consists of water level elevations at each grid cell that can be
plotted as a contour map for one point in time or as a time-series graph at a single location.
Post-processing of model results into usable graphics is perFormed using a combination of semi-
automated GIS and database program applications. Figure 3-20 presents a simplified
schematic of the modeling process.
Model construction, calibration, and operation were built upon 12 years of effort by OCWD staff
to collect, compile, digitize, and interpret hundreds of borehole geologic and geophysical logs,
water level hydrographs, and water quality analyses. The process was composed of 10 main
tasks comprising over 120 subtasks. The major tasks are summarized as follows:
• Finalize conceptual hydrogeologic model layers and program GIS/database applications to
create properly formatted MODFLOW input data files. Over 40 geologic cross sections were
used to form the basis of the vertical and lateral aquifer boundaries.
• Define model layer boundaries. The top and bottom elevations of the three aquifer system
layers and intervening aquitards were hand-contoured, digitized, and overlain on the model
grid to populate the model input arrays with a top and bottom elevation for each layer at every
grid cell location. Model layer thickness values were then calculated using GIS.
• Develop model layer hydraulic conductivity(K)grids. Estimates of K for each layer were
based on (in order of importance): available aquifer test data, well-specific capacity data, and
lithologic data. In the absence of reliable aquifer test or specific capacity data for areas in
Layers 1 and 3, lithology-based K estimates were calculated by assigning literature values of K
OCWD Groundwater Management Plan 2015 Update 3-26
Section 3
Basin Hydrogeology
to each lithology type (e.g., sand, gravel, clay)within a model layer and then calculating an
effective K value for the entire layer at that well location. Layer 2 had the most available
aquifer test and specific capacity data. Therefore, a Layer 2 transmissivity contour map was
prepared and digitized, and GIS was used to calculate a K surface by dividing the
transmissivity grid by the aquifer thickness grid. Initial values of K were adjusted during model
calibration to achieve a better match of model results with known groundwater elevations.
• Develop layer production factors for active production wells simulated in the model. Many
production wells had long screened intervals that spanned at least two of the three model
layers. Therefore, groundwater production for each of these wells had to be divided among
each layer screened by use of layer production factors. These factors were calculated using
both the relative length of screen within each model layer and the hydraulic conductivity of
each layer. Well production was then multiplied by the layer factors for each individual well.
For example, if a well had a screened interval equally divided across Layers 1 and 2, but the
hydraulic conductivity of Layer 1 was twice that of Layer 2, then the calculated Layer 1 and 2
production factors for that well would have been one-third and two-thirds, respectively, such
that when multiplied by the total production for this well, the production assigned to Layer 1
would have been twice that of Layer 2. For the current three-layer model, approximately 25
percent of the production wells in the model were screened across more than one model layer.
In this context, further vertical refinement of the model (more model layers) may better
represent the aquifer architecture in certain areas but may also increase the uncertainty and
potential error involved in the amount of production assigned to each model layer.
• Develop basin model water budget input parameters, including groundwater production,
artificial recharge, and unmeasured recharge. Groundwater production and artificial recharge
volumes were applied to grid cells in which production wells or recharge facilities were located.
The most uncertain component of the water budget—unmeasured or incidental recharge—
was applied to the model as an average monthly volume based on estimates calculated
annually for the OCWD Engineer's Report. Unmeasured recharge was distributed to cells
throughout the model, but was mostly applied to cells along margins of the basin at the base of
the hills and mountains. The underflow component of the incidental recharge represents the
amount of groundwater flowing into and out of the model along open boundaries. Prescribed
groundwater elevations were assigned to open boundaries along the northwest model
boundary in Los Angeles County; the ocean at the Alamitos, Bolsa, and Talbert Gaps; the
mouth of the Santa Ana Canyon; and the mouth of Santiago Creek Canyon. Groundwater
elevations for the boundaries other than the ocean boundaries were based on historical
groundwater elevation data from nearby wells. The model automatically calculated the
dynamic flow across these open boundaries as part of the overall water budget.
• Develop model layer storage coefficients. Storage coefficient values for portions of model
layers representing confined aquifer conditions were prepared based on available aquifer test
data and were adjusted within reasonable limits based on calibration results.
• Develop vertical leakage parameters between model layers. Vertical groundwater flow
between aquifer systems in the basin is generally not directly measured, yet it is one of the
critically-important factors in the model's ability to represent actual basin hydraulic processes.
Using geologic cross-sections and depth-specific water level and water quality data from the
OCWD multi-depth monitoring well network, staff identified areas where vertical groundwater
OCWD Groundwater Management Plan 2015 Update 3-27
Section 3
Basin Hydrogeology
flow between the modeled aquifer systems is either likely to occur or be significantly impeded,
depending on the relative abundance and continuity of lower-permeability aquitards between
model layers. During model calibration, the initial parameter estimates for vertical leakage
were adjusted to achieve closer matches to known vertical groundwater gradients.
• Develop groundwater contour maps for each model layer to be used for starting conditions and
for visual comparison of water level patterns during calibration. Staff used observed water level
data from multi-depth and other wells to prepare contour maps of each layer for November
1990 as a starting point for the calibration period. Care was taken to use wells screened within
the appropriate vertical interval representing each model layer. The hand-drawn contour maps
were then digitized and used as model input to represent starting conditions.
• Perform transient calibration runs. The nine-year period of November 1990 to November 1999
was selected for transient calibration, as it represented the period corresponding to the most
detailed set of groundwater elevation, production, and recharge data. The transient calibration
process and results are described in the next section.
• Perform various basin production and recharge scenarios using the calibrated model. Criteria
for pumping and recharge, including facility locations and quantities, were developed for each
scenario and input for each model run.
Define objectives
Compile data
Analvze data Develop Hvdroqeoloqic Model
geologic cross sections aquifer boundaries
X-Y trend graphs transmissivity
�� contour maps storage coefficient
I water chemistry data basin water balance
* Build Computer Model �
create grid
Revise Hvdroqeoloqic Model digitize layers
revise geologic cross sections, create data input files
inferred faults define model conditions
refine conceptual model
� Calibrate Model
� � � � _� match historical water levels
adjust until results acceptable
�
Run Model Scenarios
develop production/recharge alternatives
set up data for each alternative
output results as contour maps and hydrographs
Figure 3-20: Model Development Flowchart
OCWD Groundwater Management Plan 2015 Update 3-28
Section 3
Basin Hydrogeology
3.7.1 M�d�l Calibration
Calibration of the transient basin model involved a series of simulations of the period 1990 to
1999, using monthly flow and water level data. The time period selected for calibration
represents a period during which basic data required for monthly transient calibration were
essentially complete (compared to pre-1990 historical records). The calibration period spans at
least one "wet/dry" rainfall cycle. Monthly water level data from almost 250 target locations
were used to determine if the simulated water levels adequately matched observed water levels.
As shown in Figure 3-21, the calibration target points were densely distributed throughout the
basin and also covered all three model layers.
After each model run, a hydrograph of observed versus simulated water levels was created and
reviewed for each calibration target point. In addition, a groundwater elevation contour map for
each layer was also generated from the simulated data. The simulated groundwater contours
for all three layers were compared to interpreted contours of observed data (November 1997) to
assess closeness of fit and to qualitatively evaluate whether the simulated gradients and overall
flow patterns were consistent with the conceptual hydrogeologic model. November 1997 was
chosen for the observed versus simulated contour map comparison since these hand-drawn
contour maps had already been created for the prior steady state calibration step. Although
November 1997 observed data were contoured for all three layers, the contour maps for Layers
1 and 3 were somewhat more generalized than for Layer 2 due to a lower density of data points
(wells) in these two layers.
Depending on the results of each calibration run, model input parameters were adjusted,
including hydraulic conductivity, storage coefficient, boundary conditions, and recharge
distribution. Time-varying head boundaries along the Orange/Los Angeles County line were
found to be extremely useful in obtaining a close fit with observed historical water levels in the
northwestern portion of the model.
Fifty calibration runs were required to reach an acceptable level of calibration in which model-
generated water levels were within reasonable limits of observed water level elevations during
the calibration period. Figures 3-22 through 3-24 show examples of hydrographs of observed
versus simulated water levels for three wells used as calibration targets.
OCWD Groundwater Management Plan 2015 Update 3-29
Section 3
Basin Nydrogeology
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Noteworthy findings of the model calibration process are summarized below:
� The model was most sensitive to adjustments to hydraulic conductivity and recharge distribution.
. In other words, minor variations in these input parameters caused significant changes in the
model water level output.
• The model was less sensitive to changes in storage coefficient, requiring order-of-magnitude
changes in this parameter to cause significant changes in simulated water levels, primarily
affecting the amplitude of seasonal water level variations.
• The vast amount of observed historical water level data made it readily evident when the model
was closely matching observed conditions.
,�
• Incidental (unmeasured) recharge averaging approximately 70,000 afy during the 1990-1999
period appeared to be reasonable, as the model was fairly sensitive to variations in this recharge
amount.
• Groundwater outFlow to Los Angeles County was estimated to range befinreen 5,000 and 12,000
afy between 1990 and 1999, most of this occurring in Layers 1 and 3.
• Groundwater flow at the Talbert Gap was inland during the entire model calibration period,
indicating moderate seawater intrusion conditions. Model-derived seawater inflow ranged from
500 to 2,700 afy in the Talbert Gap and is consistent with chloride concentration trends during the
OCWD Groundwater Management Plan 2015 Update 3-30
Section 3
Basin Hydrogeology
calibration period that indicated inland movement of saline groundwater in these areas.
• Model-derived groundwater inflow from the ocean at Bolsa Gap was only 100-200 afy due to the
Newport-Inglewood Fault zone, which offsets the Bolsa aquifer and significantly restricts the
inland migration of saline water across the fault.
• Model adjustments (mainly hydraulic conductivity and recharge) in the Santiago Basins area in
Orange significantly affected simulated water levels in the coastal areas.
• Model reductions to the hydraulic conductivity of Layer 2 (Principal Aquifer)along the Peralta Hills
Fault in Anaheim/Orange had the desired effect of steepening the gradient and restricting
groundwater flow across the fault into the Orange area. These simulation results were consistent
with observed hydrogeologic data indicating that the Peralta Hills Fault acts as a partial
groundwater barrier.
• Potential unmapped faults immediately downgradient from the Santiago Basins appear to restrict
groundwater flow in the Principal Aquifer, as evidenced by observed steep gradients in that area,
which were reproduced by the model. As with the Peralta Hills Fault, an approximate order-of-
magnitude reduction in hydraulic conductivity along these suspected faults achieved the desired
effect of reproducing observed water levels with the model.
(Model Layer 1 --Anaheim Forebay)
200
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SO
11/1/90 11/1/92 11/1/94 11/1/96 71/7/98
Figure 3-22: Calibration Hydrograph of Monitoring Well AM-5A
OCWD Groundwater Management Plan 2015 Update 3-31
Section 3
Basin Hydrogeology
(Model Layer 2 -- Santiago Pit Area)
200 � ,
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(All Three Model Layers --Garden Grove)
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-60
11/1/90 11/1192 71/1/94 11/7/96 71/7/98
Figure 3-24: Calibration Hydrograph for Monitoring Well GGM-1 ,
OCWD Groundwater Management Plan 2015 Update 3-32
Section 3
Basin Hydrogeology
3.7.2 Model Advisr�r}o Panel
The model development and calibration process was regularly presented to and reviewed by a
Model Advisory Panel. This technical panel consisted of four groundwater modeling experts who
were familiar with the basin and highly qualified to provide insight and guidance during the
model construction and calibration process. Twelve panel meetings were held between 1999
and 2002. The panel was tasked with providing written independent assessments of the
strengths, weaknesses and overall validity and usefulness of the model in evaluating various
basin management alternatives. Two memoranda were prepared: one at the completion of the
steady-state model calibration and steady-state scenarios (Harley et al., 1999) and one at the
completion of the transient model calibration and initial transient basin operational scenarios
(Harley et al., 2001). Key conclusions and findings of the panel regarding the transient model
are summarized below.
• Transient modeling has substantially improved the overall understanding of processes and
conditions that determine how and why the basin reacts to pumping and recharge. This
improved understanding, coupled with the model's ability to simulate existing and possible
future facilities and altemative operations, significantly improves the District's potential ability to
enhance and actively manage basin water resources.
• Modeling has helped verify major elements of the basin conceptual model and has been
instrumental in clarifying:
o Variations in the annual water balance
o Hydrostratigraphy of the basin
o Horizontal flow between basin subareas
o The potential degree of interconnection and magnitude of vertical flow between major
aquifers
o The potential hydraulic significance of the Peralta Hills Fault in the Anaheim Forebay
o Variations in aquifer hydraulic properties
o The relative significance of engineered versus natural recharge and groundwater
outflow within the basin
o Numerous other issues and conditions
• The ability of the model to simulate known and projected future conditions will evolve and
improve as new data become available and updated calibration runs are completed.
• Parameters used to set up the model appear to be within limits justified by known, estimated,
and assumed subsurface conditions based upon available historic data.
• Initial transient calibration completed using a nine-year calibration period (1990-1999) is
considered adequate to confirm the initial validity of the model for use in evaluating a variety of
potential future projects and conditions.
• Areas of the basin that could benefit from future exploration, testing, monitoring, analysis
and/or additional model calibration were identified.
• The model is not considered appropriate for assessing detailed local impacts related to new
recharge facilities or well fields. These impacts should be assessed using more detailed local
sub-models and by conducting detailed field studies.
OCWD Groundwater Management Plan 2015 Update 3-33
Section 3
Basin Nydrogeology
• The model does not, nor is it intended to, address water supply availability, cost, water quality,
or land subsidence.
Recommendations of the panel included suggestions that thorough documentation be prepared
on model configuration and calibration and that the model calibration period be extended as
new data become available.
3,7.3 Gro�n�water �d1��el l�pdate and Applicatio�s
OCWD staff update the basin groundwater model approximately every three to five years,
guided by new information warranting the effort (new wells in critical areas) or by needed model
evaluations using the most recent years, e.g., estimating the groundwater outflow to Los
Angeles County. Major changes and improvements over the past five years include:
1. Model conversion from UNIX to PC using the Groundwater Vistas as the Graphical User
Interface.
2. Extension of the model transient calibration through WY 2010-11. The new calibration
period is November 1990 to June 2011 which includes a wide range of basin storage
conditions as well as a wide range of hydrologic conditions.
3. Addition of several new Talbert Barrier injection wells and the addition of two new
recharge basins, La Jolla and Miraloma Basins.
Typical applications of the Basin Model include estimating the effects of potential future
pumping and recharge projects on groundwater levels, storage, and the water budget. The
storage coefficients determined during the original Basin Model calibration are also used to
estimate annual change in groundwater storage.
The Basin Model was also used in 2011 to estimate the effects of additional recharge from new
Miraloma Basin on the GWRS subsurface retention time buffer area located in the Anaheim
Forebay. In accordance with the CDPH Draft Groundwater Replenishment Regulations at the
time of the permit's adoption, OCWD developed a six-month buffer area downgradient of
Kraemer and Miller Basins using a sulfur hexafluoride (SF-6) artificial tracer test, inside which
drinking water wells could not be constructed or operated (Clark, 2009). OCWD subsequently
acquired the Miraloma property and developed it into a recharge basin intended primarily for
GWRS water recharge. The three-layer Basin Model and the existing tracer test-determined
buffer area were used to determine the necessary modifications to the Anaheim Forebay GWRS
buffer area.
Two other applications of the Basin Model were related to operation of the Talbert Seawater
Barrier. The first was to guide the planning, location and hydraulic effectiveness of
supplemental injection wells for the Talbert Barrier during pre-GWRS planning activities. The
second was to estimate the general flow paths and subsurFace residence time of barrier
OCWD Groundwater Management Plan 2015 Update 3-34
Section 3
Basin Hydrogeology
injection water to delineate the Talbert Barrier's recycled water retention buffer area. Inside of
this area new drinking water wells are not allowed, as required by the California Department of
Public Health requirements contained within the original permit to operate the GWRS (RWQCB,
2004, OCWD, 2005).
3.7.4 Talb�r� Gap Mod�l
Between 1999 and 2000, OCWD contracted with Camp Dresser& McKee Inc. to develop a
detailed groundwater flow model of the Talbert Gap and surrounding area for the purpose of
evaluating and estimating the amount and location of fresh water injection wells needed to
control seawater intrusion under current and projected future basin conditions. The Talbert Gap
modeling effort was undertaken as part of the design scope of work for Phase 1 of the GWRS,
which included expansion of the existing Talbert Barrier. The configuration and initial calibration
of the Talbert Gap Model and further model refinement and calibration were documented by
Camp Dresser& McKee Inc. (2000, 2003).
Consistent with the Basin Model Advisory Panel's findings, OCWD determined that a more
detailed model of the Talbert Gap was necessary to evaluate the local water level changes
associated with various potential injection barrier alignments and flow rates. The Talbert model
comprises an area of 85 square miles, 13 Layers (seven aquifers and six aquitards), and
509,000 grid cells (250 feet x 250 feet horizontal dimensions). Figures 2-25, 2-26 and 2-27
show the model area, Talbert Model Calibration Wells and boundary wells and layering
schematic, respectively.
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Figure 3-25: Talbert Gap Model and Basin Model Boundaries
OCWD Groundwater Management Plan 2015 Update 3-35
Section 3
Basin Hydrogeology
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OCWD Groundwater Management Plan 2015 Update 3-36
Section 3
Basin Hydrogeology
Key findings of the Talbert Gap groundwater model are summarized below.
• Depending on the amount of basin production, particularly near the Talbert Barrier, 30 mgd
(approximately 34,000 afy)of injection will substantially raise water levels, yet may not be
sufficient to fully prevent seawater intrusion in the Talbert Gap. Additional injection wells beyond
those planned for Phase 1 of the GWRS might be required.
• Under projected 2020 conditions, the future Talbert Barrier may require an annual average
injection rate of up to 45 mgd based on the results of existing analyses. This estimated future
injection requirement will be further evaluated as additional data are collected.
• The Talbert model inland boundaries do not coincide with hydrologic or geologic features, e.g.,
recharge area, faults. Therefore, simulated water levels are highly influenced by the time-varying
water levels specified along the boundaries. For future Talbert model predictive runs, the basin
model should be used to generate water levels that can then be specified along the inland
Talbert model boundaries.
• The Talbert model was less sensitive to adjustment hydraulic conductivity and storage coefficient
than the basin model, primarily because of the stronger influence of the specified-head
boundaries in the Talbert model.
3.7.� Alamifi4s Barrier Madel
The Alamitos Seawater Intrusion Barrier was constructed by OCWD and the Los Angeles
County Department of Public Works (LACDPW) in 1965 to protect the Central Basin of Los
Angeles County and the Orange County Groundwater Basin from seawater intrusion through
the Alamitos Gap. The OCWD and the Water Replenishment District of Southern California
(WRD) purchase and provide the injection supply, which is primarily recycled water augmented
with imported water. Barrier operations are described in Section 7.
Elevated chloride concentrations were observed inland of the barrier, especially near the
southeast portion of the barrier within Orange County, which suggested that seawater intrusion
was occurring through and around the barrier into the Orange County Groundwater Basin. In
2008 and 2009, OCWD identified critical data gaps and installed new monitoring wells at three
sites near the Orange County portion of the barrier in order to collect data to evaluate the extent
and location of possible seawater intrusion in the area.
In 2010 OCWD, WRD and LACDPW contracted with INTERA, Inc. to develop the Alamitos
Barrier Flow Model (ABFM) and the Alamitos Barrier Transport Model (ABTM). These models
were developed to simulate the relative differences in chloride transport, barrier performance for
the existing barrier, and three selected barrier expansion configurations. The objectives of the
models were to: (1) determine the existing and future potential for seawater intrusion in the
Alamitos Gap and subsequent barrier expansion requirements, (2) optimize month-to-month
operations of the existing barrier injection wells and (3) determine the travel time and
OCWD Groundwater Management Plan 2015 Update 3-37
Section 3
Basin Hydrogeology
percentage of recycled injection water reaching nearby drinking water wells to fulfill regulatory
permit requirements.
The groundwater flow and solute transport models used the industry-standard computer codes
MODFLOW (groundwater flow) and MT3D (solute transport). The model was constructed so
that it can be operated by staff from any of the three agencies (OCWD, WRD and LACDPW)
from a desktop personal computer using off-the-shelf industry-standard software and
independently-run new simulations.
Key findings of the models:
1. The dominant flow direction across and around the barrier into Orange County was
found to be primarily west to east, rather than wrapping around the ends of the barrier in
a south to north direction, as was previously thought.
2. Per-well injection capacity is limited due to relatively low aquifer hydraulic conductivities
throughout most of the Orange County portion of the barrier.
3. Additional barrier injection is required to prevent further intrusion through or around the
barrier.
4. Increasing injection, along with a westerly extension of the barrier in Long Beach to the
Seal Beach Fault, would likely halt further seawater intrusion into Orange County,
however, cut-off plumes of elevated salinity would likely continue to migrate easterly into
Orange County landward of the barrier.
A well calibrated groundwater model along with data from existing wells allowed the three
agencies (OCWD, WRD, and LACDPW)to better assess and plan for necessary expansion of
barrier facilities, as well as prioritize and optimize operation of the existing facilities. The models
provided important new insight into the behavior of the hydrogeologic system in the vicinity of
Alamitos Gap and the behavior and operation of the barrier.
One application of the model was to help evaluate the Alamitos Barrier Improvement Project,
which proposed to increase the injection capacity of the Orange County portion of the Alamitos
Barrier. A total of eight new injection well locations were proposed along the east portion of the
barrier. At each well locations, 2 to 4 depth-specific wells were assumed to inject into a specific
aquifer unit (C, B, A, or I zones).
OCWD Groundwater Management Plan 2015 Update 3-3$
WATER SUPPLY MONITORING
�.
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OCWD staff collecting sample in Santa Ana River
OCWD's comprehensive monitoring programs are conducted to safeguard the
` basin's wafer quality and to operate the basin for long-term sustainability.
Monitorinq programs include water quality data from over 2.000 wells
• Groundwater elevations collected annually at OCWD monitoring wells
• All groundwater producers report production totals every six months
• OCWD conducts Title 22 water quality monitoring for Producers
• Additional monitoring for contamination sites and for seawater intrusion
• Recycled water monitored daily, monthly, or quarterly for general minerals,
metals, organics, and microbial constituents
• Surface water monitoring includes Santa Ana River throughout the watershed
Water Resources Management Svstem
• Database stores well information, historical and current data, sub-surface
geology, water levels, and water quality
• Reports generated for a variety of purposes and for several agencies
Water Sample Collection and Analysis
• In 2014, OCWD water quality staff collected over 17,000 samples for analysis
• Most water quality samples analyzed at OCWD's Advanced Water Quality
Assurance Laboratory
Section 4
Water Supply Monitoring
E�TI � 6R �UPPLY CJi�IT+C� 1
4.� ��TR�au�fi�o�
OCWD's monitoring programs are a vital component of improving groundwater management
and assuring sustainable basin management by:
• Establishing a safe and sustainable level of groundwater production;
• Monitoring coastal water quality and seawater intrusion;
• Monitoring for potential groundwater contaminants;
• Protecting the quality of surFace water and recycled water used for groundwater
recharge and assuring that such recharge is protective of groundwater quality; and
• Assuring that the groundwater basin is managed in full compliance with all relevant laws
and regulations.
4.2 GRQUNDIIVATER M4NITC)RING
OCWD collects samples and analyzes water elevation and water quality data from
approximately 400 District-owned monitoring wells (shown in Figure 4-1) as well as between
200 and 220 privately-owned and publically-owned large and small system drinking water wells
that are part of OCWD's Title 22 program, shown in Figure 4-2. OCWD also has access
agreements to sample a number of non-District-owned monitoring wells and privately-owned
irrigation, domestic and industrial wells, shown in Figure 4-3. Inactive wells are included in
District monitoring programs when feasible. An inactive well is defined as a well that is not
currently being routinely operated but is capable of being made an operating well with a
minimum of effort. The number and location of wells that are sampled change regularly as new
wells come online and old ones are abandoned and destroyed.
The District collects, stores, and uses data from wells owned and sampled by other agencies.
For example, data collected by the Water Replenishment District of Southern California from
wells in Los Angeles County along the Orange County boundary are part of the network of wells
evaluated to determine annual groundwater elevations and are used for basin modeling.
Another example is a network of wells that are owned and operated by the U.S. Navy for
remediation of contamination plumes in the cities of Irvine, Seal Beach and Tustin.
Wells sampled under various monitoring programs change in response to fluctuations in the
number of available wells, basin conditions, observed water quality, and regulatory and non-
regulatory requirements. A comprehensive list of all wells in OCWD's database can be found in
Appendix E. This list includes well name, owner, type of well, casing sequence number, depth,
screened interval, and aquifer zone monitored, when known.
In some cases well depth and screened intervals are listed on the data base as unknown but
these wells are included because water quality or elevation data continues to be collected by `���
the owner or operator and this data and used in a OCWD monitoring prog�am, in groundwater
OCWD Groundwater Management Plan 2015 Update 4-1
Section 4
Water Supply Monitoring
modeling, or other basin program. Wells on the list also include inactive wells when water
quality or water elevation data continues to be collected or the data is utilized in one or more
current basin program.
The list includes wells located outside of District boundaries. These are included for a number
of reasons. For example, all wells that are related to operation of the Alamitos Barrier that are
located in Los Angeles County are monitored by OCWD in managing seawater intrusion along
the Orange County-Los Angeles County border. Los Angeles County wells are also used to
model the Orange County Groundwater Basin as groundwater flow is unrestricted across the
�. � W,�..� .����,� �������� .�
county line. In other cases,
:e�,,� �������� J,.��• � ��; �.
_ � � r.� � {�,��, a new well that is under
������� �.��?t'��. �� � � ���� �°��'������ construction appears on
.�...�� a :� ro�
��. '� '` ��� � `� ° ���� �,��.'�� ��° the list but the well depth
�,• �c.� ,,a �,
� ,� „�� ��` � � and screened intervals
� '`� � � �`� � ��,��`��� have yet to be
.: � �
�r �� �� ��r �^— "
�°,
� �
� ���� ' � � ��� ^��'���'' ��'. .� �'�"� incorporated into the
�
�
" � ���� �` � ���� � �� ''�' , ����'� WRMS database.
+ � �; � �.,
� • . r��� ��'��� ��
�� ' • ��" ��,. -^;,, ° �.. X Groundwater sampling is
:� ..
r, :t�r' �" �i
� � ���'�� "�'�-� ,�� � conducted in accordance
� �_ .,,. g �
`�' • ' � � ` �����. ` with ASTM protocols or
� � � � ♦
�: � � � ; �
��,,,� � � . ���� , ^�u. . � �° ,���r �,� theirfunctional equivalent
,,�,�� � � � �+ ,�°�� �r'���� ` � ' � `�,:� (ASTM D4448 - 01(2013),
�-� ����� � � �� � '� ��t� -: � Standard Guide for
� '"' a^o
�'`�.,, �� � , � � �� � y; �: � � a Sampling Ground-Water
�'� �'� � ���� �' � � *• ��' `> �� ������{� �� Monitoring Wells).
�.� �,�,; ���� � �, �� � .• .,�° :
, �+ ��,� } �=;� �s. �
�"��, �� � � � � �` �%�,� ��� Groundwater elevation
.ti� *s ,�� � � "< ` � .�, �;�
., ,,� �� ��,,�� �, ,° �� and monthly production
,,� � �
'�.�: � �°��_ ���' � � ����� � data are used to quantify
,r � � � '� � �� � ��� '� total basin pumping
w � E ,✓ �� l� �����y ��f .�`r �
,- � ��. = 3°, �° .���� ' evaluate seasonal
s �`"""�...,,t, f ��"� . � ocwoMamto�„9vv�u p� grOU11C�W8t2P I@Vel
0 t0.000 20,00� 1r ♦ OCWp MuR�port Monitoring VYeR y:
�F�� �� � ;.,-»;o������ry fluctuations and assess
""�� ` � � � �� '� � basin storage conditions.
Figure 4-1: OCWD-Owned Monitoring Wells
Comprehensive water quality monitoring programs fall roughly into th�ee categories:
(1) compliance with permits and drinking water regulations, (2) basin management, and (3)
projects for research and other purposes. Water quality samples and water level data are
collected at frequencies necessary for short- and long-term trend analyses, for analysis of the
basin as a whole and to focus on local or sub-regional investigations.
Thresholds that trigger a change in a monitoring program include (1) a recommendation by the
GWRS Independent Advisory Panel (see explanation in Section 6)for resampling or increased
OCWD Groundwater Management Plan 2015 Update 4-2
Section 4
Water Suppiy Monitoring
monitoring of a particular constituent of concern; (2) a recommendation by the Independent
Advisory Panel that reviews OCWD use of Santa Ana River water for groundwater recharge and
related water quality; (3) a change in regulation or anticipation of a change in regulation; (4) a
constituent in a sample approaches or exceeds a regulatory water quality limit or Maximum
Contaminant Level, notification level, or first time detection of a constituent; (5)the computer
program built by OCWD
to validate water quality r��� � �;;�,- -��-.
data prior to transfer to -_- � ��..�r r"� � ���"�� `� ' �''�� �� ��'��.
� � �
the WRMS data base ��� ` "��� '`"" �'������ `" �� �
, � : r� ' � �..
flags a variation in t�� � R � �`��� � � ��
��" ��
r, ������ � ��
historical data that may r�s � �,�, � � ���°� '''"` ` ` � ''�"°
� �+�, ��� � t r�`
� indicate a statistically ��� ���� � '� � �' � �� ; ��~�' .�
significant change in �° �,�9 �'�' �; s �����``�� ° � �
� � �,; �. H � .,�w; �,
water quality; (6) •�"� �' �' � � �' -= � �,��
�v � �" � s� ��r. �� ` �� - , � �
�, �.
analysis of water quality "� �� �� � � � �` � �� ;'� � �,�
trends conducted by � �' � �' �' �� "� "� � ��r �� ���' � �H�� �� � �. s�-�'
�
water quality, ,> `� '�" ��� '�� �,� � � ��� ���
4' "5 3r �` �`
hydrogeology, or �� ' � � � � � r` � s`.� , � ���t-0. � .
� �.
��.. ���
recycled water , � �; � '� � �; �` ;`��° �� � �;
s° � 4,, �,
production staff indicate ;�'`� `��'` � ��' � :�
�� �
a need to change �'�..,� � ��'��' +c�'s,��y
monitoring; and (7) ti � � `��� �°��� '
� �
*
OCWD initiates a special �`:, �'`�� ��� � � �'��`,�`�'„�`�� ,� ;,'
study, such as �`'�:,� � �F���'� � �£ �rsp�,{� �..�� r.�� �.
quantifying the removal � �d d` '�
"�.� � +� :�� ,,' �� �` ,,r,
�
4`+ �y �
��e.,'a � ��� r 1 ��S # v A,�,���'� `�:
of contaminants using �, .,,� � a �� � � � �, � � �. �
treatment wetlands or � �� � � ������� � � �� ���_
W� �`� E � � �, .. �� ������ ��' -;�",
testing the infiltration rate * '4•-...., '' ' "" $
s O,w, ✓+ .. '9 Act'rue Wrge-syatem D�Ncing Water Wefl .
of a proposed new o ,o.� p.� `°•.' � �tNe�����@m o��,k�,g��.wBq ;
�Faae �",.•ocw�ea,fldan �
recharge basin. � � �-��" �
� ��Y- ��� . �. _
Figure 4-2: Large and Small System Drinking Water Wells
in Title 22 Monitoring Program
4.2.1 �roundwater Prc�ducti�n Monitc�ring
All entities that pump groundwater from the basin are required by the District Act to report
production every six months and pay a Replenishment Assessment. Private individual well
owners pumping less than one acre-foot a year pay an annual flat fee instead of the
Replenishment Assessment and do not have to report their production.
Approximately 200 large-capacity municipal and privately-owned supply wells account for
ninety-seven percent of production. Large-capacity well owners report monthly groundwater
production for each of their wells. The production volumes are verified by OCWD field staff.
Production data are used to manage basin storage and collect revenues.
OCWD Groundwater Management Plan 2015 Update 4-3
Section 4
Water Supply Monitoring
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N �~'••,.,� $& � � Ya� �a�����i
A„ti � �� �¢� $ � �.
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w y~ � �f �n.^��j� �„ K� �., €5��y , �•
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� `�-...,, ,•� tt �� ir,a�,He aw��w�
0 10,OOU iQ.UCO �..�� ;��, OU�er ActNa Produclwn�WeN . �
�FaN '��'w ��;
G._..i ocwD Bountlan
_ . .. .. . . . .���
Figure 4-3: Private Domestic, Irrigation, and Industrial Wells in
OCWD Monitoring Programs
�.2.2 �ra�ndwater Elevati�n Manit�ring
Production and monitoring wells in the basin are measured for groundwater elevation at varying
intervals, as explained below:
• Water elevation measurements are collected for every OCWD monitoring well at least
once a year with some wells measured bi-weekly;
• Monitoring of municipal wells may be conducted more frequently depending on well
maintenance, abandonment, new well construction, and related factors;
• Over 1,000 individual measuring points are monitored for water levels on a monthly or
bi-monthly basis to evaluate short-term effects of pumping, recharge or injection
operations; and
• Additional monitoring is done as needed in the vicinity of OCWD's recharge facilities,
seawater barriers, and areas of special investigation where drawdown, water quality
impacts or contamination are of concern.
Beginning in 2011, OCWD began reporting seasonal groundwater elevation measurements to
the Department of Water Resources (DWR) as part of the California Statewide Groundwater
OCWD Groundwater Management Plan 2015 Update 4-4
Section 4
Water Supply Monitoring
Elevation Monitoring (CASGEM) program. The CASGEM program was created by DWR in
response to legislation passed in 2009 (SBx7-6). This amendment to the California Water Code
required DWR to develop a statewide groundwater elevation monitoring program to track
seasonal and long-term trends in groundwater elevations in California's groundwater basins.
The CASGEM program aims to improve
�,:
�� ' �� ���� �s��, ��� , ��°�� management of groundwater resources
�� : , ,
�� `� �` '�,��� �`�`� -_� * by establishing a permanent, locally-
�� ; .
�
�� �'���� ���`������� � � � �'`��'� ��� ��� �� ;�;� managed program of regular and
.-.-. � 3 �w�..
�. . a �,
��� � . � ��'�` f �����; systematic monitoring in all of California's
� t. � �'. �
�r� � + ��,, a,, ��� � � �. � "��' �� alluvial groundwater basins
� �� � �,, ...sr
� �, � �m'�� � y:���
''� �� � �..� ,-,� ��3� OCWD has been designated as the
` � ��� �_'� ���� � ,�-�`�; Monitoring Entity for the Orange County
�� , �,b�--�''� . ���� ���� � ����� Groundwater Basin. A Monitoring Entity is
��� �• � � � �� � ����� a local agency that voluntarily takes
��.��,� + �� � �,s`.�,�� � „��� responsibility for coordinating groundwater
r'''�r � • � � ` � w� F � Ievel monitoring and reporting for all or part
�``�,.� ,� � � � � . �'d� ;�w�� of a groundwater basin. Wells monitored
�� �� � � �' � �_ .� ,,` ' under the CASGEM program are listed in
�.� � e . �� 3 # {�
`•�,.. �n '�`�, � ���� a� � � � , ' �� �'��>,�� Appendix E. The monitoring network
�-� �`�:�� � � � �� ����,�
�.., .� �� �� a ��' � : �`���,"; consists of monitoring stations distributed
" �'', � ��� `�`� � � � � � ` ° � ����� '� laterall and verticall throu hout the � ���
�! .� E r `��,�.�"�j"�� ���,�e����,�,�� Y Y 9
� �,,,�w 1 <. � ^^°^��^^�� Orange County Groundwater Basin as well
� .,,,� ,3 �� i Multport Monftonnp WbM
o �o.� �.� ''�` ' � ` � �^�W�P���^�� � as the La Habra Subbasin as shown in
��� �i ���,���ry ... ... Figure 4-4.
Figure 4-4: Wells in CASGEM Program
4.2.3 W���f QU�II$y 4C11tOriC9C� Federal and State Drinking Water
Standards
OCWD monitors water quality in production wells on
behalf of the Groundwater Producers for The Federal Safe Drinking Water Act
compliance with state and federal drinking water �SDWA)directs the Environmental
Protection Agency(EPA)to set health-
regulations (Figure 4-5). Samples are analyzed for based standards (Maximum Contaminant
more than 100 regulated and unregulated Levels or MCLs)for drinking water to
chemicals at frequencies established by regulation protect public health against both naturally-
as shown in Table 4-1. occurring and man-made contaminants.
EPA establishes MCLs for bacteriological,
The total number of water samples analyzed per inorganic, organic, and radiological
year varies year-to-year due to regulatory constituents. Califomia administers and
requirements, conditions in the basin and applied enforces the federal program and has
research and/or special study demands. In 2014, adopted its own SDWA,which may contain
over 17,000 samples were collected by the Water more stringent state requirements. The
Quality Department and analyzed at OCWD's state- regulations implementing the California
certified Water Quality Assurance Laboratory, of SDWA are referred to as the Title 22
which 24% were for drinking water. Drinking Water Standards.
OCWD Groundwater Management Plan 2015 Update 4-5
Section 4
Water Supply Monitoring
Table 4-1: Monitoring of Regulated and Unregulated Chemicals
CA SWRCB Division of Drinking Water
Title 22 Drinking Water: Groundwater Source Monitoring Frequency-Regulated Chemicals
_ _ _
. _ _ _ _ _
Chemical Class Fre uenc Monitorin Notes
Inor anic-General Minerals Once eve 3 ears
Inor anic-Trace Metals Once eve 3 ears
Nitrate and nitrite Annuall New wells sam led uarterl for 1 st ear
Detected>50°/a MCL Quarterl
Perchlorate New wells sam led uarterl for 1st ear
State Detection limit=4 ppb; OCWD RDL
Detected>DLR Quarterl =2.5 b
Non-detect at<DLR Once eve 3 ears
Volatile or anic chemicals VOC Annuall New wells sam led uarterl for 1st ear
Detected VOC Quarterl
New wells sampled quarterly for 1 st year; if
S nthetic or anic chemicals SOC non-detect,susce tibilit waiver for 3 ears
Must sample 2 consecutive quarters once
Simazine Once eve 3 ears eve 3 ears
New wells sampled quarterly for 1 st year
(initial screening)to determine reduced
Radiolo ical monitorin fre uenc for each radionuclide
Detected at > 1/2 MCL to MCL Once eve 3 ears Per radionuclide
Detected at > DLR< 1/2 MCL Once eve 6 ears Per radionuclide
Non-detect at<DLR Once eve 9 ears Per radionuclide
EPA and DPH Unre ulated Chemicals
Monitoring completed for existing wells in
CDPH :4-Inorganic and 5-Organic 2001-2003; new wells tested during 1st
chemicals year of operation
EPA UCMR1 -List 1: 1-Inorganic
and 10-Or anic chemicals Two required GW UCMR1 program completed Jan 2001 -
EPA UCMR1 -List 2: 13-Organic samales:
Dec 2003
chemicals (1)Vulnerable period:
May-Jun-Jul-Aug-Sep
�������z�;���:� ������ (2)5 to 7 months before
or after the sample � �
Chern I� L�t���'�rrt,�l���t�.�ah��-
` collected in the vulnerable
�� � � period. No further testing ���� � '
�w��ac:�i� ci�t�� �� ��
� , after completing the finro
�������"� � ' ��� ' required sampling events
EPA U�MR�Li�#1;:7-i�t�p�nx��r�� AII v�rat�r.t��iN'�i�s aervin��1.E�,qO��aeoPl�.
14�Or anic t�r�rrricefs Mc�nit : .lan��13._0�;2t�1�
�411 wate�r:c�#iii�s s�rvingr p�al�rtitm
>1t)U,0£��!E�'1#�iet�tl s�terrts
EPA UCM�3�i.is#2:'T-�ic ser�ing�c�b�,i�1�ja�.
chemicals Hormones Mc�nitnri ocJ;.1�r�24i�-D�c 2015
OCWD Groundwater Management Plan 2015 Update 4-6
Section 4
Water Supply Monitoring
Figure 4-5: �
OCWD Staff ��
��,�.
Collecting Water "���" ���`�
Sample at �._.�—.—
Production Well
��
OCWD's water quality monitoring program for drinking°water wells includes
• 5ampling of each production well (Figure 4-5)every three years (annual sampling of approximately
one-third of production wells on a rotating basis)for general minerals, metals and secondary
Maximum Contaminant Levels{MCLs)constituents;
• Sampling of every production well for volatile organic compounds (VOCs) and nitrates;
• Monitoring of production wells when{1)VOCs or perchlorate are detected (2}when nitrate
concentrations exceed 50 percent af the primary MCL or(3)constituents exceed the secondary
MCL;
• Testing for selected chemicals on the unregulated lists, chemicals with Notification Levels or new
chemicals of concern at varying frequencies;
• Monitoring of newly-constructed wells for synthetic organic chemicals (SOCs)for four consecutive
quarters to provide seasonal data for the California Division of Drinking Water and deterrnining long-
term monitoring frequencies; and
• Collecting and analyzing 1,161 samples in 2013 and 2014 ta comply with the Federai Unregulated
Contaminant Monitoring Rule Phase 3.
Monitorin4 for UnreQulafed Chemicals
EPA and the Califomia Division of Drinking Water require moniforing for specified, unregulated
chemica/s. These are chemicals that do not have an established drinking water standard, buf are
new priority chemicals of concem. Monitoring provides information regarding their occurrence
and/evels detected in drinking wafer supply wells as fhe first assessment step to determine if the
establishment of a standard(MCL) is necessary. Wells must be sampled firoice within 12 months
to comply with the unregu/afed chemical monitoring rules. Monitoring under the Federal
Unregulated Confaminant Monitoring Ru/e Phase 1 and Phase 2 was comp/eted in 2003 and
2010, iespecfive/y. Monitoring for the Federa/Unregu/afed Contaminant Monitoring Ru/e Phase
3 began in January 2013 to be completed by December 2015.
OCWD Groundwater Management P1an 2015 Update 4-7
Section 4
Water Supply Monitoring
�.2,4 Mcanitorin� of Gro�r�d��t�r Con#aminatior� Pfumes
�v�' �� � ���� ,����� ��� � � In response to the discovery of VOCs in
� � � ��,� the mid-1980s, OCWD developed a
° ���°��� I � �� com rehensive ro ram to monitor
`� --1-- �,a�,��a,�� �i - P P 9
i r���:a���� A= � ;` contaminated groundwater in the basin.
��"'- ��-�-�—. `_ ���_._ � �� =� ^�,� � £� ` ��� � This e�ensive monitorin ro ram led to
-- -- d � � 4� ��.-__ ___ 9 P 9
�<� :a� �, � �� ��3� � � the discovery of the former EI Toro
' � ' M a r i n e C o r p s Air S ta tion so lven t p lumes
' .,� �� � ��' ` �" ��, ,�.,.
6 �mm�m��� ���`�-��=��~ � �~�~���° located in the City of Irvine.
x �a� ,� � — � .
��y y '
� ��__ �:,9 ������ � � � � �. �.�,.�
� � � � � ' Continued monitoring and installation of
_......_. .,y_� .:.. at E__�_,_,;��E, �t; , �.wr:,�Na� : .. �
j � �� f � _, � a d d i t i o n a l m o n i t o r i n g w e l l s a l s o r e s u l t e d
� � w�---`'� � � ' ; in the discovery of two large plumes of
�,, �--'" -�-�--�r�: '
���� „ t�:,�� contaminated groundwater, one located
__ . � __...__ �: Actr.s�a�gcsrs�em a�oduc,nn weu �
-�—"� �'�` � -_ �="` ����� '� '��°S^�`�'�°^���'�'�°^"'� in the north part of the basin in the
� .� u+xctive ProOuctron Wex
� "°"'�'"°"�" Anaheim/ Fullerton area and the other
ty`y`n:y 4 Ot�er 1141we PrpC�ttron 4Jetl
`` � ' located in the south part of the basin in
N .,;�. a �� �
�`� � �� the City of Santa Ana. Groundwater
� � .
contamination in these areas is the
Figure 4-6: North Basin Groundwater result of industrial activities, some dating
Protection Program Monitoring Wells back to the 1950s and 1960s.
.__ _ . . _ _ _. . __ .
�=v-,j�E OCWD has and continues to work with
v : h�,��r
the appropriate regulatory agencies
� � � A���"�,��� �. overseeing identified sites that have
�. t���t �� .. � �
� � _ - �������� ��� ��� �� ������ � �"� ''y �� ���� contributed to groundwater
k9.
� ' "`-� contamination. OCWD has also
, � �
___ _ a � � f� ��
'' �F � �`' �"# embarked on developing projects to
n � ��,
` � - ,� ,,.�.�rc. �.
� � ; , r�- . �,° hydraulically contain and eventually
��� �, �: ,� � .
� ` � � ' clean up the contaminated groundwater.
_ ,,.�=m�A., ._ � �" ; � ��
� ���� � � The northern and southern regions of
� '�� contaminated groundwater are being �
�� � � ;
__ ; _ p,P��.� �:. �
, , addressed by the District's North and
� � � .�� ���� South Basin Groundwater Protection
� ���� ��� � ��� �``'���y - �� Programs, respectively. These projects
� � � � `� �����,� �� ��°����,���� are described in Section 8. The current
��� ����� � �� " s ,,�,���ro��sy�emP���b�,��� � groundwatermonitoring networks
rn'�„'� Cathodic Protection Nhll �
fr�< � ;, ,�a«Nm P,od��,��W�„ ' developed for these projects are shown
� � -,�;�•
�"°�"� "'� -�� ��� � "�°"°`�'°"'e" in Figures 4-6 and 4-7.
� ♦ MullipoR Monitofirp Nkll � �� y.�qp
�^�+-✓�Y�� � Olhar AcGve Productan VYe11 �f„�
�
�,,� `*.
Figure 4-7: South Basin Groundwater
Protection Program Monitoring Wells
OCWD Groundwater Management Plan 2015 Update 4-8
Section 4
Water Supply Monitoring
4,2.5 Mc�r��to�ing for Seawat�r Intrusion
Continual monitoring of groundwater near the coast is done to assess the effectiveness of the
Alamitos and Talbert Barriers and track salinity levels in the Bolsa and Sunset Gaps. Over 425
monitoring and production wells are sampled semi-annually to assess water quality conditions
during periods of lowest (winter) and peak production (summer).
As explained in Section 7, the Alamitos Seawater Intrusion Barrier, located along the border of
Los Angeles and Orange Counties, is jointly operated by OCWD and the Los Angeles County
Department of Public Works (LACDPW). LACDPW maintains and samples all barrier
monitoring and injection wells including those owned by OCWD. Data is shared between the
two agencies with a joint report on the status of barrier operations prepared on an annual basis.
Water levels are measured monthly in many of the coastal wells to evaluate seasonal effects of
pumping and the operation of the injection barrier, as shown in Figure 4-8. A small subset of
coastal wells is equipped with pressure transducers and data loggers for twice daily
measurement and recording of water levels.
�,. � ���.��� ��- . ���:�_ ���� Key groundwater
~ � ������'.�� � . ���� �.��`� �
�� �:,��----_-�-� ��''�, ;_ �'� � . � ����� � monitoring parameters
t ,
'" �` "'*' �:.. �M� � �,� ��� � �. used to determine the
,�; ,.�° �`,� �f��
a' � �w � �
� � r• � a =y�� ,�,��� �� �, a , effectiveness of the
� �� • ����� • •
� � ,�_ ����� � � ���, o� barriers include water
� ` ��� ���'` ��` �` level elevations,
� i ������ � � ��. �
; � � ����`� ���
�;� chloride, TDS,
�-s � � � � �
��� �� ° �'�� electrical conductivity,
��` �� -� and bromide.
. .��'°'".; ' 6�� "�,.�, �: i'. .:�i�
`�`" a. �a � �.����; Groundwater elevation
� � >.�
� ,�, � r��.
�� �� � tt.� � �� `. ' � � contour maps for the
�, � . � � � aquifers most
, �,�° ,.
x,
,,,.��"f ��� �� �x T' �`�„ ` '��� susceptible to seawater
�
�,� ��� ���� �� �� � � ,��.�' `" intrusion are prepared
� �
`�� � .������ `;��� �` �� ��,�_� � to evaluate whether or
� � �. �� � � � �°;��x �.
`�,k ,� � � � �",, � f'� not the freshwater
"`�.., `�, �` ���� ��,� �� �;'� ' ��,�� � mound developed by
'`•. ``�=.�� ������� �'-��'�� � �"';` � � ���'�r�� the barrier injection
,,� :�
�,,,�: � � *�N���.SYy�*�«��w�,� � wells is sufficient to
'� ���'`~ � � �,�,�,�`�"`ron'�� � prevent the inland
w b -` a ��� r
� ' � '�°"�°"'�"�� movement of saline
s .,, � � „�`'�� i N0.ria�portA�bnl�«ing4W� �
o ,a.� �.� `""'�.' � ���e��� water.
i
�EeNt L._..1 a{.'N�Bdt1fM3AlY �
� , ��,- ..< .� �. a ,.,�
Figure 4-8: Seawater Intrusion Monitoring Wells
OCWD Groundwater Management Plan 2015 Update 4-9
Section 4
Water Supply Monitoring
�4.3 RECYCLED WATER MOl�ITC�RI�1G
Recycled water produced by the GWRS is used for injection into the Talbert Seawater Intrusion
Barrier and for groundwater recharge, as described in Section 6. Use of GWRS water is
regulated by the State Water Resources Control Board —Santa Ana Region and the Division of
Drinking Water. Similar monitoring is performed at the WRD-owned Leo J. Vander Lans
Advanced Water Treatment Facility that supplies recycled water to the Alamitos Seawater
Barrier for injection.
GWRS product water is monitored daily, weekly, and quarterly for general minerals, metals,
organics, and microbiological constituents as summarized in Table 4-2. Focused research-type
testing has been conducted on organic contaminants and selected microbial species.
Table 4-2: Groundwater Replenishment System Product Water Quality Monitoring
CATEGORY TESTING FREQUENCY
General Minerals monthly
Nitrogen Species (NO3, NO2, NH3, Org-N) twice weekly
TDS weekly
Metals qua�terly
Inorganic Chemicals quarterly
Microbial dai4y
Total Organic Carbon (TOC) daily
Non-volatile Synthetic Organic Compounds (SOCs) quarterly
Disinfection Byproducts quatterly
Radioactivity quarterly
Emerging Constituents quarterly
To comply with the permit to operate the GWRS, groundwater samples are taken from 35
monitoring wells at nine sites to monitor GWRS water after percolation or injection. Samples
are also taken from additional wells downgradient and along the groundwater flow path to
collect data for long-term analysis of the effect of using GWRS supply for groundwater
recharge. The location of these wells is shown in Figure 4-9.
Because of the low concentration of salts in GWRS water, OCWD initiated a Metals Mobilization
Study to analyze for trace metals in selected wells near and downgradient of basins used for
recharge of GWRS water. The GWRS Independent Advisory Panel recommended this study to
evaluate the potential of GWRS water to alter existing groundwater geochemical equilibria, such
as causing metals currently bound to aquifer sediments to be released when GWRS water
mixes with an aquifer matrix that is in equilibrium with the ambient groundwater.
OCWD Groundwater Management Plan 2015 Update 4-10
Section 4
Water Supply Monitoring
OCWD is investigating the feasibility of injecting 100 percent GWRS water directly into
the Principal Aquifer in the central part of the basin. The Mid-Basin Injection
Demonstration Project consists of a test injection well (MBI-1) along with seven nearby
monitoring wells (SAR-10/1-4 and SAR-11/1-3) located approximately three miles north
of the Talbert Barrier, along the GWRS pipeline at the Santa Ana River and Edinger
Avenue in Santa Ana.
Ambient water quality
;� � ��, .�.�� �� � � � conditions are monitored in the
K� ' ����� :�:�, � ��#�`
� .�-� �-� ��-��� � M � vicinity of the demonstration
��.�"`� � � �� ��'�`� � ° �� ���� project to establish a water
�v
--� �--�, �� `�� � �� �� �,�� �_� ' � quality baseline to evaluate the
� �� � ��
£ - � �� ���'�.�� potential of inetals mobilization
� t �� :;� �� ,
� � �
� ��.: ��.�`�� � �� �� �� upon injection of GWRS water
: � �y _
�_-� �=���� ��=" �� and to access any other water
4 ��
�' ` � quality changes should they
��; �, a r
� �
���' ,� � �;
� �` � � �� � ° �`�° � occur once injection of GWRS
� �� � �. ,.� .
, � R � a
� f � �� � water at the site commences.
�`"�,,,t � � � � � �`' „,�.� ,
� �� � � Quarterly samples are taken
��� . �'� �c� , . 1;.�,.,vr.
�
'� ���� �� �� and analyzed for microbial,
�r � , �� ,
`��� � � � �� � �,���� �� general minerals, trace metals, �� �
`-�� '�„� � � �� ��, � "` .� semi-volatile organic
�, `�� � � �' ��� ; '��J � ��� � �, � � compounds, and radiological
� ��`� x.� ��' t r � ��
�; � ���
� �`-�-�� � +��� �� �� � ��,����� constituents. Data from this
� ���., � � � ��,� ; Mid-Basin Injection
.
w�- E `„� � ������� �,� :£�` Demonstration Project will
•� � ""��.. �` � � �� ��. �'��� ���- e��� �� support the design and
o �aocn �eaoo �. � �' � o�vxs�a,rpvue, ..
k��.� `� � �;���,, permitting of a future, full-scale
'�� � �:��,�.�:� ��.�: �..
project.
Figure 4-9: GWRS Monitoring Wells
4.4 SURFACE WATER IV�ONITt�RI�IG
Surface water from the Santa Ana River is the predominate source of recharge supply for the
groundwater basin. As a result, the quality of the surface water has a significant impact on
groundwater quality. Several on-going programs monitor the condition of Santa Ana River
water. Characterizing the quality of the river and its impact on the basin is necessary to verify
the sustainability of continued use of river water for recharge and to safeguard a high-quality
drinking water supply for Orange County. OCWD monitoring sites along the river and its
tributaries are shown in Figure 4-10.
OCWD Groundwater Management Plan 2015 Update 4-11
Section 4
Water Supply Monitoring
�,4.1 Santa Ar�a River c�nit�arir�g
OCWD captures and recharges nearly all of the non-storm flow (base flow) in the Santa Ana
River that is released through the Prado Dam, which consists predominately of tertiary-treated
and disinfected wastewater discharged upstream of Prado Dam. The District assesses the long-
term impacts on groundwater quality from use of this water for groundwater recharge.
Santa Ana River Water Quality and Health Study
The Santa Ana River Water Quality and Health (SARWQH) Study (OCWD, 2004)was a
voluntary$10 million eight-year study that applied advanced water quality characterization
methods to assess both surface water and related post-recharge groundwater quality. The
multi-disciplinary study design included an examination of hydrogeology, microbiology, inorganic
and organic water chemistry, toxicology and public health. The organic water chemistry
component included an analysis of trace (low concentration) constituents and dissolved organic
compound characterization.
Research for the SARWQH Study was conducted by scientists, researchers and water quality
experts from numerous organizations, including Stanford University, Lawrence Livermore
National Laboratory, USGS, Oregon State University, and Metropolitan Water District of
Southern California.
Nafiona/WaterResearch Institute Report At the request of OCWD, the
National Water Research Institute
The NWRI Panel concluded:"Based on the scientific data �NWRI) conducted an independent
collected during the SARWQH Study, the Panel found that:
review of the results from the
"The SAR met all water-quality standards and SARWQH Study. NWRI assembled
guidelines that have been published for inorganic and a group of experts in the fields of
organic contaminants in drinking water. hydrogeology, water chemistry,
No chemicals af wastewater origin were identified at microbiology, and the other
concentrations that are of public health concern in the requisite fields to form the Scientific
SAR, in water in the infiltration basins,or in nearby Advisory Panel. This Panel met
groundwaters." annually during the study to review
The constituents that were considered included non- the results and provide
regulated chemicals(e.g., pharmaceutically active recommendations on future
chemicals)and contaminants of concern that arose during Work. The results affirmed that
the course of the SARWQH study(e.g., OCWD recharge practices using
n-Nitrosodimethylamine[NDMAJ). Santa Ana River water are
The unprecedented classification of the major components Protective of public health, but that
of DOC and the transformations that occur within these continued adaptive monitoring
chemical classes as water moves downstream and into the Would be necessary. Findings from
aquifer provided significant new evidence to support the the SARWQH Study provided
conclusion thatthe product water is suitable for potable information necessary for the
consumption and is also becoming cflmparable to other planning and permitting of other
sources of drinking water, such as the Colorado River, in OCWD projects, such as the
its organic profile."(NWRI,2004� GWRS.
OCWD Groundwater Management Plan 2015 Update 4-12
Section 4
Water Supply Monitoring
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� � - � �< � '
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, � �
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. . ._. M°�'$�.� . ..,.
Figure 4-10: Surface Water Monitoring Locations
Santa Ana River Monitoring Program
OCWD continues to implement a comprehensive surface and groundwater monitoring program,
referred to as the Santa Ana River Monitoring (SARMON) Program that includes an annual
review and recommendations by the NWRI SARMON Independent Advisory Panel (IAP).
Monitoring activities include sites on the Santa Ana River, Anaheim Lake, Santiago Basin and
selected downgradient monitoring wells from the recharge basins to provide data on travel time
and to assess water quality changes.
On-going monthly surface water monitoring of the Santa Ana River is conducted at Imperial
Highway near the diversion of the river to the off-river recharge basins and at a site below Prado
Dam. Sampling frequencies for selected river sites and recharge basins are shown in Table 4-3.
Several points on the river and key tributaries to the river above Prado Dam, as shown in Figure -
4-10 are also monitored annually for general minerals and nutrients.
OCWD Groundwater Management Plan 2015 Update 4-13
Section 4
Water Supply Monitoring
Beginning 2015, the monitoring program was revised to shift monthly monitoring from Anaheim
Lake to Imperial Highway. As a result of declining base flows in the Santa Ana River, more
water is recharged in the riverbed and less is diverted to Anaheim Lake for percolation.
Although a site on Temescal Creek is in the sampling program, it was last sampled in 2008
because the site has been dry since 2009.
Table 4-3: Surface Water Quality Sampling Frequency within Orange County
(A= annual, S= semi-annual, M = monthly, Q = quarterly)
SAR SAR Anaheim Miraloma/ Santiago
CATEGORY Below (mperial Lake Kraemer/ Basins
Dam Hwy Miller Basin
General Minerals M M Q Q M
Nutrients M M Q Q M
Metals Q Q Q Q Q
Microbial M M Q M M
Volatile Organic Compounds (VOC) Q M Q Q M
Semi-Volatile Organic Compounds Q Q Q Q Q
(SOC)
Total Organic Halides (TOX) M M Q M
Radioaetivity Q Q Q Q Q
Perchlorate M M Q Q M
Chlorate Q M Q Q M
NDMA Formation Potential (NDMA-FP) S
Chemicals of Emerging Concern (CEC) Q Q Q Q Q
Notes' � Monitoring for NDMA-FP was conducted monthly at Imperial Highway during 2008 and quarterly
between 2009-2012 at Imperial Highway and Anaheim Lake, as well as at two sites at Prado Wetlands
(upstream and downstream of the wetland ponds). Since 2015, monitoring occurs at the reduced frequency
indicated in the table.
2 Samples from Imperial Highway are tested for a full suite of CECs. The other sites are tested for a
reduced list of analytes.
4.4.2 Ba�in IVlar�itoring Pragram Annual R�port of Santa Ana Water Quality
The Basin Monitoring Program Task Force (Task Force)was formed in 1995 to determine and
monitor the extent of and to evaluate the impact of increasing concentrations of Total Inorganic
Nitrogen (TIN) and Total Dissolved Solids (TDS) in groundwater basins in the Santa Ana River
Watershed (see section 9.3 for more details). As a result of this work, the Santa Ana Regional
Water Quality Control Board requires that the Task Force prepare an annual report of the Santa
Ana River water quality. Monitoring locations are shown in Figure 4-11.
OCWD Groundwater Management Plan 2015 Update 4-14
Section 4
Water Supply Monitoring
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Figure 4-11: Basin Monitoring Program Task Force Monitoring Locations
4.4.3 Santa Ana River Watermaster Monitoring
The Santa Ana River Watermaster produces an annual report in fulfillment of requirements of
the Stipulated Judgment in the case of Orange County Water District v. City of Chino, et.al.,
Case No. 117628-County of Orange, entered by the court on April 17, 1969. The Judgment
settled water rights between entities in the Lower Area of the Santa Ana River Basin
downstream of Prado Dam against those in the Upper Area tributary to Prado Dam. The court-
appointed Watermaster Committee consists of representatives of four public entities who are
responsible for fulfilling the obligations in the Judgment. These four are the Orange County
Water District representing the Lower Area and San Bernardino Municipal Water District,
Western Municipal Water District, and the Inland Empire Utilities Agency, representing the
Upper Area.
The Watermaster annually compiles the basin hydrologic and water quality data necessary to
determine compliance with the provisions of the Judgment. The data include records of stream
discharge (flow) and quality for the Santa Ana River at Prado Dam and at Riverside Narrows as
well as discharges for most tributaries; flow and quality of non-tributary water entering the river;
rainfall records at locations in or adjacent to the watershed; and other data that may be used to
support the determinations of the Watermaster.
Data collected by the USGS at finro gaging stations, "Santa Ana River Below Prado" and "Santa
Ana River at Metropolitan Water District Crossing" are used. Discharge data at both stations
consists of computed daily mean discharges based on continuous recordings and daily
OCWD Groundwater Management Plan 2015 Update 4-15
Section 4
Water Supply Monitoring
maximum and minimum and mean values for electrical conductivity (EC) measured as specific
conductance and twice monthly measured values for total dissolved solids.
Stream gage data collected by the USGS at the following gaging stations are also used: Santa
Ana River at E Street in San Bernardino, Chino Creek at Schaefer Avenue, Cucamonga Creek
near Mira Loma, and Temescal Creek in the City of Corona. Precipitation data is collected at the
USGS Gilbert Street Gage in San Bernardino and by OCWD in Orange County.
4,4.4 Nletre►palitan Water Dis�rict Import�d Wat�r
Imported water purchased by the District from the Metropolitan Water District of Southern
California (MWD) is monitored for general minerals, nutrients and other selected constituents.
The District may also monitor metals, volatile organics and semi-volatile organics (e.g.,
pesticides and herbicides). MWD performs its own comprehensive monitoring and provides data
to the District upon request.
4,4.5 F'radQ W��land�
Flow into and out of the District's Prado Basin wetlands are monitored to evaluate changes in
water quality and to evaluate the effectiveness of the wetlands treatment. More details
concerning the operation of the Prado Wetlands can be found in Section 8.5. OCWD has been
monitoring the Prado Wetlands since 1998. Water samples are analyzed for field parameters,
biological, inorganic, and organic constituents. Research is currently being conducted at the
Prado site to evaluate alternative methods of wetlands treatment.
�.4.6 Err�erging Gonsti�uen�s
OCWD participates in a watershed-wide Emerging Constituents Monitoring Program
administered by SAWPA. This group was formed in 2010 to characterize emerging constituents
in 1) municipal wastewater effluents, 2)the Santa Ana River at various locations, and 3)
imported water. Three years of testing (2011-2013)were completed as directed by the
Regional Water Board (R8-2009-0071). OCWD monitored two sites twice a year on the Santa
Ana River for this program. Future testing may be conducted after completion of a statewide
program currently being developed by the SWRCB.
OCWD monitors two surface water sites quarterly on the Santa Ana River and at various
locations within District recharge facilities below Prado Dam. Samples are analyzed for
pharmaceuticals, endocrine disruptors and other emerging constituents such as personal care
products, food additives, and pesticides. In addition, OCWD samples for CECs at the diversion
into the Prado Wetlands once during the winter and fall and monthly from spring through
summer as part of a focused study with ReNUWit (see Prado POWUP Project described in
Section 4.4.7). The District also conducts a groundwater monitoring program testing for
representative constituents as described in Section 8.8.
OCWD Groundwater Management Plan 2015 Update 4-16
Section 4
Water Supply Monitoring
4.4.7 �p�cial Surfa�e W�ter Studies
OCWD conducts additional water quality studies as needed. Current studies are described
below.
Sediment Removal Studies
One of the key impediments to maximizing the recharge capacity of the surFace water system is
clogging, which is primarily caused by the deposition of silts and clays in the recharge basins.
An extensive research project was conducted to evaluate various methods that could be used to
reduce or remove the suspended sediments from surface water prior to recharge. The finro
methods that were identified for additional demonstration-scale testing were Riverbed and Cloth
Filtration, which are discussed in Section 5.6.
GWRS Focused Studies and Membrane Testing
These studies evaluate treatment removal efficiencies and membrane integrity assessment
(new and old membranes), focusing on specific water quality assessments and may include use
of external contract lab support for specific process points to aid in possibly obtaining greater
removal credit for the GWRS treatment system.
Prado POWUP Project
Prado Open Water Unit Process Wetlands (POWUP) Research Project is funded by the
National Science Foundation. OCWD is conducting this project with ReNUWIt (Re-inventing the
Nation's Urban Water Infrastructure)and four primary member institutions (Stanford University,
UC-Berkeley, Colorado School of Mines, and New Mexico State University). OCWD's Prado
Wetlands are being used to test how wetlands treatment can be optimized with unit processes
in series. The project will test the removal of pharmaceuticals and nitrates from wastewater
effluent and effluent-dominated surface waters and assess the overall costs and benefits of
alternative constructed wetland treatment systems.
4.� 19V�TER R�S�U CES NIAI�l�C'aEI1l��NT �°r'�TENa: DATABAiE
MAi�AGE ENT
Data collected by OCWD are stored in the District's custom electronic database called the
Water Resources Management System (WRMS). WRMS provides a central point of access and
storage of hydrologic and hydrogeologic information. The database contains comprehensive
well information, current and historical data, as well as information on sub-surface geology,
water level and water quality. This database provides for subsequent retrieval and analysis of
data or preparation of data reports and data submittals to other agencies. OCWD analyzes and
reports data in a number of regular publications as shown in Table 4-4.
WRMS is an integrated system that is comprised of four primary components: (1) a relational
database management system (RDBMS) using Oracle, (2) a geographic information system
OCWD Groundwater Management Plan 2015 Update 4-17
Section 4
Water Supply Monitoring
(GIS) using ArcGIS, (3) a computer-aided drafting system (CAD) using AutoCAD, and (4) a web
portal with custom applications to facilitate sharing of data befinreen the systems and to provide
an interface for users to enter, report, evaluate and analyze data.
WRMS was designed to assist Orange County Water DistricYs engineers and scientists with the
management of the groundwater basin. The foundation data set is the location and attributes of
wells throughout the basin. Details about existing and historical wells, such as construction
information and lithology logs, are stored in the RDBMS. Also stored in WRMS are all the
historical and current time-series data, including water levels, water quality, production, and
injection data associated with the wells. Additionally, the RDBMS stores information about
recharge stations and percolation volumes. Typical applications include:
Aerial maps Location of proposed new wells
Water elevation contours Contamination plume maps
Maps of basin change in storage Well logs
Pumping volume Cross sections
Basin volume calculation Well diagrams and casing details
Seawater intrusion Time series data water level graphs
Maps of well location Atlases and reports
WRMS provides information in the form of reports and data extraction to agencies on a regular
basis, such as:
• Orange County Public Health Department
• California Department of Water Resources
• California Division of Drinking Water
• California Regional Water Quality Control Board
• California Department of Toxic Substances Control
• U.S. Environmental Protection Agency
• OCWD Groundwater Producers
The CAD applications query data stored in the WRMS assist the end-user in preparation of
hydrogeologic graphics. Examples of the types of graphics include geologic cross-sections and
stiff diagrams. The GIS component of WRMS provides two primary functions: production of
maps and spatial analyses for planning-level studies, and as a pre- and post-processing tool for
the numerical groundwater computer model of the groundwater basin. Spatial data used by the
GIS includes well locations, recharge basins, water level contours, street networks, as well as
additional layers, such as political boundaries. Digital aerial photography is also used for map
production work.
4.� V1i�TER SAMPLE COLLECTION A�I� ANALYSIS
OCWD's laboratory, shown in Figure 4-12, is state-certified to perform bacteriological, inorganic,
and organic analyses. The District utilizes state-certified contractor laboratories to analyze
asbestos, dioxin and radiological samples. Analytical methods approved by the Division of
OCWD Groundwater Management Plan 2015 Update 4-18
Section 4
Water Suppiy Monitoring
Drinking Water and the EPA are used for analyzing water quality samples for the drinking water
compliance program. As new chemicals are regulated, the OCWD laboratory develops the
analytical capability and becomes certified in the approved method to process compliance
samples. The amount of samples analyzed is dynamic, ranging from 600 to 1,700 samples in
any given month. In 2014, the lab handled nearly 20,000 samples for a total of 427,000
analytes.
Figure 4-12: OCWD Advanced
Water Quality Assurance Laboratory
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Water quality samples are collected in the field in accordance with approved federal and state
procedures and industry-recognized quality assurance and control protocols to ensure that
sampled water is representative of ambient groundwater or surface water conditions. Analyses
for synthetic organic chemicals (SOCs) including tests for herbicides, pesticides, plasticizers,
and other semi-volatile organics require use of 12 or more analytical methods.
Production wells that provide water for drinking water, irrigation/agriculture and industrial uses
generally have well screens located in the permeable, water-bearing zones that may tap
multiple aquifers. Therefore, water quality samples collected from these wells may represent
water from one or more aquifers with some permeable zones providing a greater contribution
than others to the overall water sample. In contrast, monitoring wells are designed and
constructed with well screens placed at a specific depth and length to provide water quality at
desired zones within an aquifer. Figure 4-13 illustrates the three monitoring well designs used
for basin-wide water quality monitoring activities: multi-point, nested and cluster.
OCWD Groundwater Management Plan 2015 Update 4-19
Section 4
Water Supply Monitoring
The multi-point well is a Westbay well design that contains a single casing with sampling ports
located at specific depths in the underlying aquifers (Figure 4-14). Individual sampling points are
hydraulically separated by packers. A computer-assisted sampling probe is used to collect a
water sample at the desired depth. The sampling port has direct hydraulic connection befinreen
the port and the aquifer, allowing groundwater to flow into a detachable stainless steel sample
container. OCWD has more than 50 multi-point wells ranging from a few hundred feet to over
2,000 feet in depth.
Sampling the nested and cluster monitoring wells may require purging of 40 to nearly 2,000
gallons of groundwater prior to sample collection. Generally, a truck equipped with one or more
Westbay Multipoint submersible pumps and a
Weii Nestea weu wen eiuster Portable generator is used to
purge and sample groundwater
from these wells. Portable
submersible pump and reel
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efficiency of sampling monitoring
wells without dedicated pumps.
One truck is outfitted with a dual
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Figure 4-13: Monitoring Well Designs
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Figure 4-14: Westbay Well Schematic
OCWD Groundwater Management Plan 2015 Update 4-20
Section 4
Water Supply Monitoring
4.6.1 F�ubEicatic�r� ofi aata
OCWD presents collected data in a number of regular publications listed in Table 4-4.
Table 4-4: OCWD Publications
Report Publication Frequency Contents
Engineer's Report on the Annua! Basin hydrology, groundwater conditions, total
Groundwater Conditions, Water groundwater production, groundwater(evels,
Supply and Basin Utilization in coastal groundwater eonditio�s, calcufation water in
the Orange Coun#y Water ` starage, imported water purchases; required by
District District Act
Santa Ana River Water Quality Annual Surface water quality data for Santa Ana River
Monitoring Report
Groundwater Replenishment Annual Data related to the operation of the GWRS and '
System Annuat Report Talbert Seawater Intrusion Barrier; required by
RWQCB permit
Santa Ana River Watermaster Annual Amounts of Santa Ana River flows at Prado Dam
Report and Riverside Narrows; required by 1969 stipulated
' judgment
Report on Graundwater Periodieally Total amounf of recharge to basin, including natural
Recharge recharge, managed aquifer recharge, source of
recharge water, 8�recharge facility performance
4.7 GRt��1NDV1fATEF� AND SURFACE 1NATER INTERACTIONS
Frequent and destructive flooding of the Santa Ana River in Orange County was the impetus for
construction of the Prado Dam in 1941. Prior to the construction of flood control facilities, the
banks of the Santa Ana River naturally overflowed periodically and flooded broad areas of
Orange County as seen in Figure 4-15. Coastal marshes were inundated during winter storms
and the mouth of the river moved both northward and southward of its present location. In the
days before flood control, surFace water naturally percolated into the groundwater basin,
replenishing groundwater supplies.
Subsequent flood protection efforts included construction of levees along the river with
concrete-lined bottoms along portions of the river. Flood risk was reduced, increased pumping
of groundwater lowered water levels and low-lying areas were filled in for development. Today,
groundwater levels throughout Orange County are low enough that the rising and lowering of
groundwater levels do not impact surface water flows or ecosystems.
From Prado Dam to Imperial Highway, the wide soft-bottomed channel supports riparian
habitats. Riparian habitat is dependent on river water released through Prado Dam, which is
predominantly treated wastewater discharged in the upper watershed when storm flow is not
OCWD Groundwate� Management Plan 2015 Update 4-21
Section 4
Water Supply Monitoring
present. In aggregate, this stretch is generally considered to be in equilibrium befinreen surface
water and groundwater based on available stream gage data, although some infiltration may
occur due to groundwater pumping in the vicinity of Green River Golf Course.
From Imperial Highway to 17�' Street in Santa Ana, the river is a losing reach with surface water
percolating into groundwater. OCWD conducts recharge operations within the soft-bottomed
river channel except for a portion of the river where the Riverview Golf Course occupies the
river channel. The river levees are constructed of either rip-rap or concrete.
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Figure 4-15: Santa Ana River in Orange County,1938
Courtesy of the Anaheim Public Library
From 17th Street to near Adams Avenue in Costa Mesa, the river channel is concrete-lined for
flood control with sloping concrete side levees and a concrete bottom. From Adams Avenue to
the coast, the channel has concrete side walls or rip-rap for flood control and a soft bottom.
Estuary conditions within the concrete channel exist at the mouth of the river where the ocean
encroaches at high tide. The tidal prism extends approximately from the ocean to the Adams
Avenue Bridge.
There are no surface water bodies within the boundaries of OCWD that are dependent on
groundwater. Therefore, there are no groundwater dependent ecosystems issues in the Orange
County Groundwater Basin.
Some areas in the basin experience relatively high groundwater levels due to perched
groundwater where shallow groundwater is impeded from flowing into deeper groundwater by a
layer of low-permeable clay known as an aquitard. Except in very low-lying areas near sea
level, the high groundwater is not close enough to the surFace to support hydrophilic vegetation.
OCWD carefully monitors water levels in the vicinity of the Talbert Seawater Barrier in order to
maintain injection well rates to assure that groundwater levels do not rise to levels that will
threaten urban infrastructure.
OCWD Groundwater Management Plan 2015 Update 4-22
MANAGEMENTAND OPERATION OF
RECHARGE FACILITIES
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Routine basin maintenance at Anaheim Lake
Management of recharge facilities to maximize groundwater recharge includes
the following:
Sources of Recharge Water Suppiies
• Santa Ana River
• Recycled water
• Imported water
• Precipitation
Facilities Oqerations
• 23 recharge facilities with storage capacity of approximately 26,000 acre-feet
• Volume of recharge estimated monthly
Recharge Studies and Evaluations
• Recharge Enhancement Working Group evaluates plans to maximize efficiency of
system and develop concepts for increasing recharge capacity
• Recharge Facilities Model developed to project additional recharge for potential
new projects
• Several studies evaluate future Santa Ana River flows
Section 5
Management and Operation of Recharge Facilities
n�� �`IC� 5 M��Jpa EI\/9ENTA D C�PERATIC�1�4 C�F
REC R�E FACIL11�1 S
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Replenishing the groundwater basin, through natural and artificial means, is essential to support
pumping from the basin. Although the amount of recharge and basin pumping may not be the
same each year, over the long-term recharge needs to approximately equal total pumping.
Recharge water sources include water from the Santa Ana River and tributaries, imported
water, and recycled water supplied by the Groundwater Replenishment System as well as
incidental recharge from precipitation and subsurface inflow.
OCWD owns over 1,500 acres of land on which there are 1,067 wetted acres of recharge
facilities. These facilities are located in the Forebay of the groundwater basin adjacent to the
Santa Ana River(Figure 5-1) and Santiago Creek.
Managed aquifer recharge began in the 1930s, in response to declining water levels in the
basin. Shortly after its formation in 1933, OCWD, in cooperation with the Orange County Flood
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OCWD Groundwater Management Plan 2015 Update 5-1
Section 5
Management and Operation of Recharge Facilities
Control District (OCFCD) began experimenting with methods to increase the percolation
capacity of the Santa Ana River Channel. Successful experiments included removing
vegetation and re-sculpting the river bank and river bottom. The District began purchasing
portions of the river channel, eventually acquiring six miles of the channel in Orange County, in
order to maximize the recharge of Santa Ana River water to the basin.
Recharge of imported water began in 1949 when OCWD began purchasing Colorado River
water from the Metropolitan Water District of Southern California (MWD). In 1958, OCWD
purchased and excavated a 64-acre site one mile from the Santa Ana River to create Anaheim
Lake, OCWD's first recharge basin (Figure 5-2). Expansion of the surface water recharge
system has continued to the present time; today OCWD operates a nefinrork of 25 facilities that
recharge an average of over 230,000 afy. Although the surface water system provides the
largest source of recharge to the basin, recharge from the seawater barriers is also an important
source of recharge.
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Figure 5-2: Anaheim Lake and Mini Anaheim Lake, in foreground with Miller and
Kraemer Basins in background
OCWD Groundwater Management Plan 2015 Update 5-2
Section 5
Management and Operation of Recharge Facilities
5.2 �C)URCES OF RECHAR�� IJVATER SllPPLI�.S
Water supplies used to recharge the groundwater basin are listed in Table 5-1. Figure
5-3 and Table 5-2 show the average annual recharge by source between Water Years
2009-10 and 2013-14.
Table 5-1: Sources of Recharge Water Supplies
Supply Sources and Description Recharge Location
Base Flow Perennial flows from the upper Santa Ana River,
watershed in Santa Ana River; recharge basins, and
predominately treated wastewater Santiago Creek
Santa Ana discharges
River Storm Flow Precipitation from upper Santa Ana River,
watershed flowing in Santa Ana recharge basins, and
River through Prado Dam Santiago Creek
Storm Flow/ Storm flows in Santiago Creek Santiago Creek,
Santiago Santa Ana River and Santa Ana River water Santa Ana River,
Creek pumped from Burris Basin via recharge basins
Santiago Pipeline
Precipitation and Precipitation and runoff from Basin-wide
Natural subsurface inflow Orange County foothills,
Recharge subsurFace inflow from basin
boundaries
Groundwater Advanced treated wastewater Injected into Talbert
Replenishment produced at GWRS plant in Barrier; recharged in
System Fountain Valley Kraemer, Miller, and
Miraloma basins
Recycled
Water Water Water purified at the Leo J. Injected into Alamitos
Replenishment Vander Lans Treatment Facility in Barrier
District of Long Beach
Southern CA
Untreated State Water Project and Colorado Various recharge
River Aqueduct basins
Imported
Water Treated State Water Project and Colorado Injected into Talbert
River Aqueduct treated at Diemer and Alamitos Barriers
Water Treafinent Plant
OCWD Groundwater Management Plan 2015 Update 5-3
Section 5
Management and Operation of Recharge Facilities
o Santa Ana River Base Flow ■Storm Flow �Imported Water
■Recycled Water �1 In-Lieu Program �Incidental Recharge
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Figure 5-3: Five Year Average Recharge by Source
Water Year 2009-10 to 2013-14 •
Table 5-2: Annual Recharge by Source, Water Year 2009-10 to 2013-14
(acre-feet per year)
Santa Ana River
Base Storm Imported Recycled In lieu Mcidental
Water Year Flow Flow Water Water Rechar e Rechar e Total
2009-10 103,000 59,400 22,QQ0 67,000 0 $3,000 334,000
2010-11 904,OQ0 78,000 29,000 67,000 10,000 94,000 382,000
2011-i2 95,000 32,000 42,000 72,000 31,000 27,000 299,000
2012-13 85,000 18,000 41,p00 73,000 0 20,000 237,000
2013-14 65,000 25,000 53,000 66,000 0 32,000 241,000
Avera e 90,000 ' 42,000 37,000 69,000 8,000 51,000 298,000
Ave�a e % 30% 14% 13% 23% 3% 17% 100°!0
Notes: (1)"Storm Water"includes total storm flow recharged in both the Santa Ana River and Santiago Creek, a
tributary of the Santa Ana River(2)"Imported wate�'includes water used for Alamitos and Talbert Barriers,water
purchased by and recharged by OCWD, MET CUP supply and MET CUP in lieu supply recharged in the Forebay.
OCWD Groundwater Management Plan 2015 Update 5-4
Section 5
Management and Operation of Recharge Facilities
5.2.1 Santa Ana River
The Santa Ana River begins in the San Bernardino Mountains and flows through the Prado Dam
to Orange County, as shown in Figure 5-4. The dam was built by the U.S. Army Corps of
Engineers (the Corps) in 1941 "for flood control and other purposes."
Water from the Santa Ana River is the primary source of water used to recharge the
groundwater basin. Downstream of the dam, OCWD diverts river water into recharge facilities
where the water percolates into the groundwater basin. A 1969 legal settlement between
OCWD and all upper watershed parties requires that a minimum of 42,000 afy of Santa Ana
River base flows reach the Prado Dam. Since the 1973, base flow has exceeded the legal
minimum, reaching a maximum of over 158,000 acre-feet in 1999. In July 2009, the State
Water Resources Control Board approved Water Rights Permit No. 21243, which provides
OCWD the right to divert and recharge up to 362,000 afy of Santa Ana River flows.
District recharge facilities are capable of recharging nearly all of the base flow. OCWD also has
rights to all storm flows that reach Prado Dam. When storm flows exceed the capacity of the
diversion facilities, river water reaches the ocean and this portion is lost as a water supply.
Storing water behind Prado Dam significantly increases the amount of stormwater that OCWD is
able to recharge into the groundwater basin.
�:
� ��:
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m
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; >
-� �:< ;.
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�r�
tY ��'*?
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� SaMa Arta Rrver YlGtershed 8oundary
0 5 1C ��J OGNA BovrMerY
�Mtlas ..... . Santa Ma Rirer
Figure 5-4: Santa Ana River Watershed
OCWD Groundwater Management Plan 2015 Update 5-5
Section 5
Management and Operation of Recharge Facilities
In the 1960s, the Corps began working with OCWD to temporarily store storm water behind the
dam. When rates of release through the dam are closely matched to the downstream diversion
capacity, OCWD is able to maximize capture of this water supply and minimize the flow of water
to the ocean. However, storing water behind the dam must be managed so as not to jeopardize
the primary purpose of the dam for flood control. This is accomplished by limiting the volume of
water stored behind the dam to a lower level during the storm season to maintain storage for
future storm events. Outside of the storm season, the Corps allows a larger storage volume to
be held behind the dam.
Agreements between OCWD and the Corps signed in 1994 and 2006 set dam operating
procedures to allow temporary storage behind Prado Dam up to an elevation of 498 feet mean
sea level (msl) during the flood season (October 1 — February 28), which equates to just under
10,000 acre-feet of storage. During the non-storm season, which extends from March 1 to
September 30, the allowable elevation increases to an elevation of 505 feet msl, which equates
to just less than 20,000 acre-feet of storage. The areas inundated behind Prado Dam and the
storage for the non-storm season and storm season pools are depicted in Figure 5-5.
� Prado Daro
� water conservation
�Tpta1 flood
coMrol capaclty
Elevatiort 566 feet ��
�,� Storage volume: �
� 174,000 acrs-feet------�D
� Tempa�ary storage � s; r;�E�
Nor�-storm seasor� � �'��; y
Elevation:505 teet �
� Storape vdume_ ,
20,000 acre-Met �
�
z.��t :
� ��,; ' �Starm s�ason
Elevatfon:498 Teet � ,�,, ,,
�o�age vdume: �
�,u� 10,000 acre-feet
�.,
� � �� ,
� �
�f� � �� � ` �� ������
r r r
� . h " i �,E t s��.s
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IG
ilM ^^�* °`'�' -� a��
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. ',q",� a°"
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k s � � �
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` 11� � f�J^C C"R'F r t �;�����:,� � �
' : .3 ,. �� �# ':�: r, »�`�``i.�b �,
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�
� t fr
�14fi$�'` , &���� 1 r�'I'� .�ty,y���� �.
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.� �INB(EIOfIt�BM � �y %� �,�(�� . � �� ,
�{
�4
� ' �� ����
. . . � � �: . . . ... �.., .n .� ... � _ ,.. ., .
Figure 5-5: Area of Inundation and Storage Volume for Water Conservation Pools
OCWD Graundwater Management Plan 2015 Update 5-6
Section 5
Management and Operation of Recharge Facilities
Both the base flow and the storm flow in the Santa Ana River vary from year to year as shown in
Figure 5-6. Recent trends show a decline in base flow, which may be a result of increased
recycling, drought conditions, declining per capita water use, and changing economic conditions
in the upper watershed. The volume of storm water that can be recharged into the basin is
highly dependent on amount and timing of precipitation in the upper watershed, which is highly
variable, as shown in Figure 5-7.
Figure 5-8 shows the amount of stormwater captured since 1936. Although storm flow
averages approximately 33 percent of the total Santa Ana River flows, only approximately half
of that amount is recharged by OCWD. This is primarily because most of the flows that are lost
to the ocean occur during relatively brief periods of high releases from Prado Dam that exceed
the District's diversion capacity. During dry years, very little water is lost to the ocean; however,
in wet years, losses can be great. In water year 1997-98, for example, the District was able to
capture and recharge over 74,000 acre-feet of storm flow, but was unable to capture
approximately 270,000 acre-feet of storm flow.
Acre-feet(x1000)
�
600 -�— - — . �
Base Flow
■ Storm Flow
500 ; — -- �
�
i
400 '
i
�
300 � - --� � �
i
;
i
2�� ; �-�--- _
I
�
100 , ���
�
j
p ; , -,
1965-66 1971-72 1977-78 1983-84 1989-90 1995-96 2001-02 2007-08 2013-14
Water Year 1965-66 to 2013-14 (Oct.-Sept.)
Figure 5-6: Annual Base and Storm Flow in the Santa Ana River at Prado Dam
Source: Santa Ana River Watermaster, 2014
OCWD Groundwater Management Plan 2015 Update 5-7
Section 5
Management and Operation of Recharge Facilities
Precipitation (inches) Accumulative Departure from Average
(inches)
50 . . _ _ _ .._ __ _ � 80
_ __ _ __ , i
• ', � Annual Precipitation ' ;
' � i• ��� [
} � Average Precipitation !
40 .._ , 60
` � --+- Accumulated Departure From Average i
�� � f e i
��. r� .; . .. ..... ........ . .. ... ... . ... . .. .
` y
♦+ �
3p ♦ t } 40
•
�R ��.
.♦ � � �a '��*
♦ Z �� � t
2� � �.. , � .. ��,'r � 2�
' .s ' �.1 y ♦ _J
�o " ; o
o ' ' -zo
1943-44 19.53-54 7963-64 19T3•74 1963$t 1993-94 2003-04 2013-14
Water Year(Oct-Sep)
Figure 5-7: Precipitation at San Bernardino, Water Year (Oct.-Sept.) 1934-35 to 2013-14
Annual Recharge ■Recharged Base Flow �� Recharged Storm Flow
Acre-feet(x1000)
Imported Water �GWRS Recycled Water
300
_ _ _ __ _ _ ___ _
_ _ _
_ _ __ _ ____
_ _ _
250 _ _ _
_ . _ _
__ _ _ _ _, _ .
_ � %
_ ;_
_ � �
200 _ _.
_ __ _ _ ._ . �, � ,
_ _ _ _ ___ _ _ _ _ ,,
150 '4�i i,,<
_ _ __ _ �'
. � �p���` � �� �� �������i
_ _ � ' �, '����
100 _ �
50
0
1936 1943 1950 1957 1964 1971 1978 1985 1992 1999 2006 2013
Year
(1936-1990 is Oct-Sept water year, 1991-2014 is Julytilune Fiscal Year)
Figure 5-8: Historical Recharge in Surface Water Recharge System
OCWD Groundwater Management Plan 2015 Update 5-8
Section 5
Management and Operation of Recharge Facilities
:5.2.2 S�ntiagn Cr�ek
Santiago Creek is the primary drainage for the northwest portion of the Santa Ana Mountains
and ultimately drains into the Santa Ana River as shown on Figure 5-9. Water from Santiago
Creek and imported water is impounded by Santiago Dam, creating Irvine Lake, which is owned
by the Irvine Ranch Water District and Serrano Water District. Downstream of Santiago Dam is
Villa Park Dam, which is a flood-control facility owned and operated by the Orange County
Flood Control District.
OCWD's Santiago Basins are located downstream of Villa Park Dam. These former gravel pits
contain a large percentage of the storage capacity within the District's recharge system and can
recharge up to approximately 125 cfs. Prior to the early 1990s, the only source of water to
Santiago Basins was runoff from Santiago Creek.
In the early 1990s, the Burris Basin Pump Station and Santiago Pipeline were constructed,
allowing Santa Ana River water to be pumped to Santiago Basins for recharge. Pumped water
can also be diverted to the creek downstream of the basins for recharge. With completion of the
Santiago Basin Pump Station in 2003, OCWD has the capacity to move water both directions in
the Santiago Pipeline. This has allowed for faster draining of Santiago Basins, freeing up
, storage for stormwater
=� capture and increasing
� � ���.
����,� the DistricYs recharge
ca acit .
f � � ��=;� P Y
�, r __ ,
�� _
�� �,� ��� � ° � '��� �'� During average rainfall
5��a�� � n�l� r:�,�.� y � ������
conditions, the District
� ; �,� �, ` ` � * � -,���
� � � :�,����:���z� �• p�� � � �,�€� captures and recharges
�'
�
'�s�f� A ���� an estimated 50 000 to
� � ���� �� ���� �� �� ���� ,
, "� '��` �,�, � � ��� � 70,000 afy of storm flow,
, � � . � with much of this
� �-���� � s ' `„�, �► recharge taking place in
�>�.ar , .�a«��.^rrvn" �:'
� .a. �, � �� the Santiago Basins.
. . . p a , ��
�a.
�a�+Tucar+aeae�E' � sar�rra � " '��� ���� � SOIII@ g�0Uf1C�W2t2�
� �.�- 8.t571YS "���, ••,`�.i"a
+ �. � ,��. � �; producers in the general
� ��`�� � � vicinity of the Santiago
�°�` - `� � �� �'� Basins have low
� - ��
�= z n�t £ ��� � � a'� "� groundwater levels at
�� - � � �,'� ���� �� ��,; . _ _ ��� „ '� ��� ;�� -� their production wells
� ,� ro�. . � . ".:�': k�' �`�. ` r�a�d ����
� � � ' �r when the amount of
� ����`�� ��� � �.�� groundwater in storage
,.�',� � ��°` �
� ��A, _ � ,�� ��� �,�"�� declines. This occurs to
w�,;�� ' _����� � �W��.�';, some extent because the
o +.�a s«�o � ����'� �� —�M��P�'�ne �� aquifer is relatively thin in
Fxt a, . ' �` w :-�:� YUa Partc Dam 9
, � �� � _ � the east Orange area
Figure 5-9: Santiago Basins and Santiago Creek
compared to the aquifer
OCWD Groundwater Management Plan 2015 Update 5-9
Section 5
Management and 4peration of Recharge Facilities
thickness in the middle portion of the groundwater basin. OCWD seeks to recharge as much
water possible in the Santiago Basins subject to various operational constraints and limitations
on the amount of available recharge water.
Currently recharge in Santiago Creek is limited to the reach befinreen Santiago Basins and Hart
Park in the city of Orange. The parking lot of Hart Park occupies the creek channel, making it
difficult to convey water safely through the park. The District is currently evaluating projects
that will allow for the lower reach of the creek downstream of Hart Park to be used for recharge
of Santa Ana River water.
5.2.3 N�tural R�charge
Natural recharge, referred to in Section 3 as unmeasured or incidental recharge, is comprised of
subsurface inflow from the local hills and mountains, (see Figure 3-5), infiltration of precipitation
and irrigation water, recharge in small flood control channels, and groundwater underflow to and
from Los Angeles County and the ocean. Since the amount of natural recharge cannot be
directly measured, it is commonly referred to as incidental or unmeasured recharge. Each year,
an estimate is made of the amount of subsurface flow that flowed across the Los Angeles-
Orange County line. In general, since the Central Basin in Los Angeles County is operated at a
' lower level than the Orange County basin, there is usually a net flow of water out of the Orange
County basin to the Central Basin. This outFlow is subtracted from the total incidental recharge
to get the net incidental recharge to the basin, which is the value reported in this document.
Figure 5-10 shows the amount of net incidental recharge from WY 2000-01 to 2013-14. Note
the correlation between amount of precipitation and net incidental recharge.
Incidental Recharge Incidental Recharge -«��Precipitation in Anaheim Precipitation
acre-feet(x1000) Inches
180 �------ ---�- ---- 40
160 -+- - .v_ � 35
I �-----�
140 -�---- _..__ _ �_. .�_�_
30
i
120 �- - —
� 25
100 --- ---_-
I
20
80 � --- — __— �
� ; 15
60 —
40 � 10
�
i !
20 � 5
i
� � - -- -- -i- 0
2000-01 2003-04 2006-07 2009-10 2012-13
Figure 5-10: Net Incidental Recharge and Precipitation, WY 2000-01 to 2013-14
OCWD Groundwater Management Plan 2015 Update 5-10
Section 5
Management and Operation of Recharge Facilities
;5.2.4 Recycled tfltat�r
The basin receives finro sources of recycled water for recharge. The main source is the GWRS,
which has capacity to produce 102,000 afy of recycled water. This water is recharged in the
surface water system and the Talbert Seawater Barrier. Operation of GWRS is explained in
detail in Section 6.
The second source of recycled water is the Leo J. Vander Lans Treatment Facility which
supplies water to the Alamitos Seawater Barrier. The capacity of the Vander Lans Treatment
Facility was expanded from 3,300 afy to approximately 9,000 afy. Only a portion of the water
recharged in the Alamitos Barrier recharges the Orange County Groundwater Basin with the
remainder recharging the Central Basin in Los Angeles County.
��.2.5 Import�d VVater
OCWD purchases imported water for recharge from the Municipal Water District of Orange
County (MWDOC), which is a member agency of MWD. Untreated imported water can be
delivered to the surface water recharge system in multiple locations, including Anaheim Lake
(OC-28/28A), Santa Ana River (OC-11), Irvine Lake (OC-13A), and San Antonio Creek near the
City of Upland (OC-59). Connections OC-28, OC-11 and OC-13 supply OCWD with Colorado
River Aqueduct water. Connection OC-59 supplies OCWD with State Water Project water and
OC-28A supplies OCWD with a variable blend of water from these two sources.
Treated imported water was used extensively for in-lieu recharge from 1977 to 2007. During
this time frame, OCWD recharged over 900,000 acre-feet of water using in-lieu recharge
purchased from MWD. The MWD discontinued the in-lieu program in 2012. When the program
was operational, OCWD would ask groundwater pumpers to participate by turning off their wells
and take imported treated water in-lieu of pumping groundwater. OCWD would pay the
pumpers the incremental additional cost of taking imported water versus groundwater to make
the cost of this water equivalent to groundwater.
Control of Quagga Mussels
Quagga mussels are an invasive species that were found in 2007 in Lake Mead, a reservoir on
the Colorado River. These mussels grow quickly to form massive colonies. Not only are natural
ecosystems disrupted, but spread of these invasives can block water intakes causing significant
disruption and damage to water distribution systems.
MWD has a Raw Water Discharge P/an to manage the spread of quagga mussels within the
imported water system. Within Orange County, the mussels were found in Irvine Lake,
Rattlesnake Reservoir, and Walnut Canyon Reservoir. Methods to control the quagga include
desiccation and chlorination.
OCWD recharges Colorado River water in Anaheim Lake, Mini-Anaheim Lake, Kraemer Basin,
La Jolla Basin, and Raymond Basin. To control the spread of quaggas, OCWD only uses
Colorado River Water in basins that can be completely drained and desiccated. As a result of
OCWD Groundwater Management Plan 2015 Update 5-11
Section 5
Management and Operation of Recharge Facilities
the quagga mussels, OCWD can no longer recharge Colorado River water in the Santa Ana
River or any other facility that cannot be fully desiccated.
5.3 SUF�FACE WATE ����IA�GE F��fLITI�S
The District's surface water recharge system is comprised of 23 facilities covering over 1,000
wetted acres and a total storage capacity of approximately 26,000 acre-feet, as listed in Table
5-3. The locations of these facilities are shown in Figure 5-11. Section 5.3.1 illustrates the
operation of the recharge system. OCWD carefully tracks the amount of water being recharged
in each facility on a daily basis.
Table 5-3: Area and Storage Capacities of Surface Water Recharge Facilities
FACILITY Wetted Area Maximum Storage
(acre-feet) Capacity (acre-feet)'
Anaheim Lake 72 2,260
Burris Basin ' 120 2,670
Gonrock Basin 25 1,070
Five Coves Basin: Lower 16 182
Five Coves Basin: Upper 15 164
Foster-Huckleberry Basin 21 630
Kraerner Basin 31 1,170
La Jof(a Basin 6.5 26
L.incoln Basin 10 60
Lit##e Warner Basin 11 225
Miller Basin 25 300
Mini-Anaheim Lake 5 13
Miraloma Basin 9.8 63
Off-River Channel 89 N/A
Olive Basin 5.8 122
Placentia Basin 9 350
Raymond Basin 19 370
River View Basin 3`6 11
Santa Ana River; Imperial to Orangewood Ave. 291 N/A
Santiaga Basins 187 13,720
Santiago Creek to Hart Park ' 10 NJA
Warner Basin 7Q 2,620
Weir Ponds 1-4 33 252
TOTAL 1,Q85 26,278
Notes: (1) Maximum storage capacity is typically not achieved for most facilities due to need to
reserve buffer space for system flow and level fluctuations. (2)Owned by Orange County Flood
Control District. Maximum storage capacity shown is the maximum flood control storage. (3) Basin
is not owned by OCWD. Owners include OCFCD, City of Orange, and MWD.
OCWD Groundwater Management Plan 2015 Update 5-12
Section 5
Management and Operation of Recharge Facilities
Three full-time hydrographers control and monitor the recharge system. These hydrographers
and other OCWD staff prepare a monthly Water Resources Summary Report, which lists the
source and volume for each recharge water supply, provides an estimate of the amount of water
percolated in each recharge basin, documents total groundwater production from the basin, and
estimates the change in groundwater storage. The report also estimates the amount of
incidental recharge, evaporation and losses to the ocean. The monthly figures are compiled to
determine yearly recharge and production totals. A monthly report from 2014 is presented in
Appendix F.
,� .
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_.� �° `_. — �� ;r,�,�,s — _�,`.,^ — � =•r���;� t
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. �s�n � &5am--�'�?axUi. � {�}e�.?.at.
� .� ��L,e Rasma$ee's� .� ���,- - ._. .�
� � . �� xfPfaz�nadS ...Vt�ttner
r .. `� $arin� �-
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�,8as�n ` � . '_ .,
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..�. . , �.an�... _ _ .. ,,,.w`�.. � Lltde "� �` �`" �
� q
' jy,�g� t$ . � � �{4:lfnei � k
r�+ .�p 1'E���,��#�~ �.83tP ..
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r e
,.t. .� 1,,,, ,�r� .� �," ,*�y,4
F 1JPCef�ivt- .� ^'' . . 1 ' " .
� Cc:es$as�a � � a � ' . ��
'� � v;'�?`�"• LGwe!FavO �Z�,��� �,� �"� � �� � { .
�: Coves 6n�n �j ; , � �� „r�,
iineoVa� . '� . ��� "�'"� '�.�k�, � ,�a� � .
^ �
Beaim �
a � .� �`�'fi
'r. �� '.;Fle;cfiar ' �J� ` �. ..
�� :�:Sasm . ,�� :� + �
� OCWD Fietd Headquarters � R'�aT `� �; �"��
�'
V+ew
-Inllatab�e Rubber Dam sd �$�^ J '°"�
.. 1 .. .as:�"� � .. ,.,�:
� �..
Transfer Tube " � ,, {„ �
�Recharpe Water PiDeline -��,�_,, �� �
-GWRS Pipeline
. . . . . . &n��tn
OCWD Recharge Basm g,,,,�;nqc e,ms�,
Khit::ld.hav . . .flemixsa ,- . •_._.� .
CRy Boundary aau� .
� �[hmna[sd
N . .,... �.. Ba�at�t � .
♦ �-�
0 � 2.U00 <,OOQ � ��� . '�
i w ��� � �� E "
�Feet ��, �
s _. ��°"'" �"
Figure 5-11: OCWD Surface Water Recharge Facilities
OCWD Groundwater Management Plan 2015 Update 5-13
Section 5
Management and Operation of Recharge Facilities
5.3.1 Surface Water Recharge System
�*� °� Water released at Prado Dam naturally
�� ` �' `� �� flows downstream and percolates through
the river's 300-400 foot wide unlined
channel bottom that consists of sandy,
permeable sediment.
� OCWD actively manages recharge in an
� �'' ��� approximate 6 mile stretch of the river
� ��,,;�`��� ""�'�;,,,d„� ��� � channel from Imperial Highway to
�
_ Orangewood Avenue. This reach covers
,. ' an area of over 290 acres
�, .
�
� ,�f
. ..
. �,�
. , � ,_�
w i ���
� a ���. ,,� �� �.. �.
a
, � �
�
Beiow F'racta�Dar� "��" ��� "������a��lll6!�
�� .� � �a �
;
, � .
�
Santa Ana River in Anaheim
,. r
�� ��"
� � `� �� .�s� � The Imperial Inflatable Dam diverts up
� � µ �°;�
2��$ � ' to 500 cfs of Santa Ana River water
»,� '�� � ,,�
+�w �' ��u` t�, 'r.. . E
� � �' ��`'•�`�� � �- �.`�- `�� into the recharge system. Flows are
����'°" �; r����.� � �� also bypassed around the dam to
�� ��� ��
� downstream facilities.
,�. ' �:r �,�;��r �,�
�� eL"' . .. .4�Jy� .ry a1
*RR", � w��:�; .. � �f�`��':I
^+,y'.. .. xL.
�
�r
P" .. �4, . � . . . ..._...
�`� �r."`��s`1.�� 1` -'�a � 34e � � •
� ;�_ Imperial Rubber Dam
�� ���, �
OCWD Groundwater Management Plan 2015 Update 5-14
Section 5
Management and Operation of Recharge Facilities
�.
,
� � ���
�
Weir Ponds 1, 2, 3, and 4, also
.��.
referred to as the Desilting System,
are used to remove sediment from
Santa Ana River water.
����� ��� Flows are split at Weir Pond 4 to
� f
�k' � � ����'"� ���, � m� ,. flow either to the Warner Basin
�.
r
�` �° '��' ��"� ��"`���� ��� � ����� ��� Subsystem (Foster-Huckleberry,
� �$�� d•.z'�<`z? �` �A�,n;``^ua o ;'b����e�
�'��� ¢ .���° �` �" �� � Conrock, Warner, and Little
� ��� t
Warner Basins)or to the Off-River
Channel
� �� � � ��
�; "�" °
� � �1� �
� ;�`
� � � � .
� �,����, � ���� �������„ � Warner Basin
�
� � • `"_ - �,d��.�>�m �'�� � .��e�
From Warner Basin, water is
conveyed by pipeline to Anaheim
Lake and then to Miller and =� � ;
Kraemer Basins. Water can then
be conveyed in Carbon Creek to
La Jolla, Placentia and Raymond ; y
� , � � � �,
Basins. �_��,�,� ,� � � E,��' b � � ,�,��. ,,s�
�-4 .�
Kraemer Basin
Water conveyed into the Off-River Channel,
which parallels the main river channel,
percolates into the sandy channel bottom. This
�� ��ii�� � �
200-foot wide channel is separated from the
<' ����,��s� �° (1, ��� Santa Ana River by a 2.3-mile-long levee.
��� ,�,er� I'�' ����,�.
�` a� Remaining flows can be recharged in Olive
�' ��� ��� � �'�� Basin or conveyed to Five Coves Basins. The
�. .
������� Five Coves Basins can also receive water
,,,,.. ;�.
� ` � ' �� �������� �-. �� directly from the Santa Ana River diverted at the
. .
�.
` '�' Five Coves Inflatable Dam.
;��.
From Five Coves, water flows into Lincoln and
Burris Basins.
Off-River Channel
OCWD Groundwater Management Plan 2015 Update 5-15
Section 5
Management and Operation of Recharge Facilities
� �
From Burris Basin, water is � ��� "� �
M �� ���� „
pumped to Santiago Basins by the � ."� �.: � � � � ��
Burris Basin Pump Station through
the 60-inch diameter, five-mile long
Santiago Pipeline. Pumped water
is percolated in the Santiago
Basins, (Blue Diamond Basin, - --
Bond Basin, and Smith Basin), ; ��.�; ��
River View Basin and Santiago °������' �� '
Creek. The Santiago Basins are �� � �� �
��:;
used to recharge and store
stormwater to be conveyed back to
recharge basins when capacity is
available.
Pumps in Burris and Santiago Basins
�� � �
allow for release of water into
������`" ��� 'd�'"�����'� �� Santiago Creek for percolation.
,_�v��.
i �J a
; �f,v1
�.� ,,,��� , .. �> �.
°��«;a a `e a Y" �.
��� �� M:+`Q.!T
�}�kA��� �F qn����!�r��1
i ,�" m. �� I 4" �9
r
�,.,
�
Santiago Creek
Lower Santa Ana River
� �.
�. .
Water that remains in the Santa Ana River is managed to maximize infiltration; levees constructed in
the river bed spread water across the width of the river channel. River water reaches the Pacific
Ocean in Huntington Beach only when flow exceeds recharge capacity, which typically occurs only
during large storm events.
Recycled water produced at the GWRS in Fountain Valley is conveyed through a 13-mile pipeline
located in the west levee of the Santa Ana River to OCWD recharge basins. GWRS recycled water is
primarily percolated in Kraemer, Miller and Miraloma Basins.
OCWD Groundwater Management Plan 2015 Update 5-16
Section 5
Management and Operation of Recharge Facilities
:�.4 leJ1AINTENANCE OF RE�HARGE FACI�ITIES
OCWD recharge basins range in depth from 10 to 60 feet. Portions of their side-walls and
bottoms are composed of natural, sandy, permeable materials that allow water to percolate into
the aquifer. Percolation rates vary depending on the size and depths of the basins; rates slow
significantly as fine-grained sediment particles accumulate on the basin bottoms. Most of the
basins can be drained and cleaned to remove this clogging layer, thereby restoring percolation
rates and increasing
, recharge efficiency.
.,�
' Percolation rates tend
to decrease with time
as basins develop a
thin clogging layer
along the bottom. The
clogging layer
develops from fine
, grain sediment
� deposition and from
� ` ,:" �,{�
� � biological growth,
shown in Figure 5-12.
Percolation rates are
�, � � �, �� �� ` ��' restored by mechanical
removal of the clogging
�' � �� �� ` layer utilizing heavy
. � �� , ` - �� �
� �� '� � '� ��` equipment such as
bulldozers and
�dl �II i
. � scrapers.
��
Figure 5-12: Recharge Basin showing Accumulated Clogging Layer
OCWD maximizes recharge in the Main River System by removing the clogging layer(Figure 5-
13) and bulldozing a series of sand levees in the river. These levees maximize recharge by
spreading the water across the width of the river to maximize the wetted surface area. Typically,
water flows at a velocity sufficient to prevent the accumulation of fine sediment and biological
growth. The riverbed is also cleaned naturally, when winter and spring stormflows wash out the
levees and scour the bottom. When necessary, heavy equipment is used to move sediments in
order to restore the high percolation rate. Sand levees remain intact until flows exceed
approximately 350 cfs, at which time they erode and water flows from bank to bank in the
riverbed. Although percolation is believed to remain high during these high flow conditions,
rates are difficult to measure.
OCWD Groundwater Management Plan 2015 Update 5-17
Section 5
Management and Operation of Recharge Facilities
. _ {�
���, :F,u<N
°°. �:� � � ��� � �. v , �,.
tx� �+i`��� � "����. ,a �� � *�mw
� > 5 ;!,� � "�}.�a a� �� '���� .��"�
� 1 � � � � ' �
`�c\ ���\�r�a esj �.<.. �.� \uW„,�'�.� ��+,a �F.°i aC`�"�':;.P'
� pe"�
�0��.., \� ����.. -
Figure 5-13: Bulldozer in Off-River Channel Removing Clogging Layer
5.5 RECHARGE STUDIES AND EVALUATfONS
The District has an ongoing program to continually assess potential enhancements to existing
recharge facilities, evaluate new recharge methods and analyze potential new recharge
facilities. The planning and implementation horizon for recharge facilities varies from a near
term horizon of five to 10 years for development of specific projects to 50-year projections of the
future availability of recharge water supplies, as described below.
�.5.1 Recharge Enhao�cement Working Grcaup
The Recharge Enhancement Working Group is comprised of staff from multiple departments
that works to maximize the efficiency of existing recharge facilities and evaluate new concepts
to increase recharge capacity. Staff from recharge operations, hydrogeology, engineering,
research and development, regulatory affairs, and planning departments meets on a regular
basis to review new data and evaluate potential new projects.
Proposed projects under investigation are continually changing as needs and conditions
change. Potential projects/concepts considered include reconfiguration of existing basins,
operational improvements to increase flexibility in the management of the basins, alternative
basin cleaning methods, potential sites for new basins, and control of sediment concentrations,
are discussed and prioritized.
OCWD Groundwater Management Plan 2015 Update 5-18
Section 5
Management and Operation of Recharge Facilities
:5.5.2 Cc�mputer iVl�d�l af �ec�a�rge F�cilities
One of the challenges the District faces in determining the value of improving existing recharge
facilities, storing more water at Prado Dam and purchasing new recharge facilities is estimating
the amount of additional water that could be recharged due to a potential project. Given the
complexity and interconnectivity of the recharge system, a model was needed to isolate the
impacts of various proposed projects in order to determine the increased recharge potential due
to a specific project.
OCWD developed the Recharge Facilities Model, which is a computer model of the District's
recharge system that simulates Prado Dam operations, Santa Ana River flow and each
recharge facility. This model is primarily a planning tool that is used to evaluate various
conditions including estimating recharge benefits if new recharge facilities are constructed,
existing facilities are improved, increased storage is achieved at Prado Dam, or baseflow
changes occur in the Santa Ana River. The model can be operated by District staff from a
desktop computer using a graphical user interface.
The Recharge Facilities Model was completed in 2009 with the assistance of CH2M HILL and is
based on GoldSim software, which is a general simulation software solution for dynamically
modeling complex systems in business, engineering and science http://www.goldsim_comJ
Home/) (CH2M HILL, 2009).
Key features of the Recharge Facilities Model include:
• Ability to simulate different surface water inflow scenarios (e.g., high base flow, low base
flow, etc.)
• Inflatable rubber dam operations (e.g., diversion rates, deflation/inflation)
• Conveyance capacity of system (e.g., pipeline and pumping capacities)
• Basin recharge capacities
. Reductions in basin capacities caused by clogging
• Maintenance thresholds that cause basins to be taken out of service and cleaned
• Different Prado Dam conservation pool elevations and release rates
• Different sedimentation levels behind Prado Dam
• Ability to add imported water to system when excess capacity is available
Output from the model includes:
• Amount of water recharged in each facility, storage at Prado Dam, release rates from Prado
Dam, storage in each facility, etc.;
• Amount of water that could not be recharged and water losses to the ocean;
• Optimal amount of cleaning operations;
OCWD Groundwater Management Plan 2015 Update 5-19
Section 5
Management and Operation of Recharge Facilities
• Available (unused) recharge capacity; and
• Amount of imported water that can be recharged using unused capacity.
The RFM is flexible and allows for the development and simulation of a wide array of different
scenarios. Figure 5-14 presents an overview of the system as it appears in GoldSim.� Examples of
how the model has been used to evaluate potential recharge projects include:
• Estimate of the additional amount of water available for recharge if the water conservation
pool behind Prado Dam is raised to 505 msl year round (see Section 5.2.1).
• Estimate of the impact of the recent trend toward decreasing base flows in the Santa Ana
River.
• Estimate of how much imported water could be purchased using unused system capacity.
.�., „
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•..+sk.. i nx.wie. W.s.tu..
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�......_..._'__'__. ___.�__._� '""
Figure 5-14: Recharge Facilities Model System Overview
5.5.3 Futur� S�r�ta Ana Riv�r Flc�v+e P�c�jectic�ns
OCWD prepares projections or works with other agencies to prepare projections of Santa Ana
River flows. The results of the projections are highly variable, as explained below.
OCWD Assessment of Future Santa Ana River Flows Below Prado Dam 2006
OCWD applied to the State Water Resources Control Board (SWRCB)for a permit to divert a
wet-year maximum of 505,000 afy of water from the Santa Ana River at the DistricYs diversion
facilities below Prado Dam. As part of the 2006 application, the SWRCB requested that OCWD
OCWD Groundwater Management Plan 2015 Update 5-20
Section 5
Management and Operation of Recharge Facilities
prepare a water availability assessment to confirm that the volume of water would be available
in the future.
To prepare the assessment, the District used flow data collected by the Santa Ana River
Watermaster which showed that more than 505,000 afy of water was recorded in the lower
Santa Ana River in recent years preceding the study. Future wet-year flow estimates were
developed taking into account planned upstream diversions to calculate conservative future wet-
year Santa Ana River flow below Prado Dam. This assessment concluded that the requested
diversion of 505,000 afy is reasonably foreseeable in future wet years downstream of Prado
Dam.
The Corps Prado Basin Water Supply Feasibility Studv, 2004
The Corps' report Prado Basin Water Supp/y Feasibility Study Main Report and Draft
Environmenta/Impact Statement, 2004 estimated future Santa Ana River flows to assist in
evaluating the flood control and water conservation capabilities of the dam. Between 1990 and
2003 the maximum flow occurred in 1993 when the USGS gage below Prado Dam recorded a
total of 571,138 acre-feet. The Corps used a 39-year hydrologic base period (federal water year
1950-1988) and Corps projected watershed conditions through 2052. These projections
factored in changes in stormwater runoff due to increased urbanization in Riverside and San
Bernardino counties and population projections as well as estimates of wastewater effluent
discharges to the river upstream of the dam.
The Corps projected that future annual flow in the Santa Ana River at Imperial Highway will
fluctuate between approximately 300,000 and 868,000 afy. These projections include a net
contribution of 21,000 afy from the nine miles of the river between Prado Dam and Imperial
Highway.
SAWPA Santa Ana River Flow Estimates 2004
SAWPA produced an independent estimate of future SAR flows at Prado Dam for the period
2010 and 2025. The estimates included baseflow and stormflow for dry, average, and wet
years. Stormflow estimates were based on the average historical peaks ranging from 18,300 to
340,300 afy. Estimates of wastewater discharges included reductions in discharge due to
increased recycling of wastewater. Base flow projections for 2025 ranged from 197,000 afy to
222,000 afy.
OCWD(Corps Studv, 2Q14
Projections of future Santa Ana River flows were developed for OCWD and the Corps to
evaluate the feasibility of increasing the volume of water that can be stored behind Prado Dam.
(WEI, 2014) An existing model developed by Wildermuth Environmental, Inc. (WEI) called the
Waste Load Allocation Model (WLAM), was used to estimate non-discharge inputs contributing
OCWD Groundwater Management Plan 2015 Update 5-21
Section 5
Management and Operation of Recharge Facilities
to river flows. The WLAM is a hydrologic simulation tool of the Santa Ana River watershed
tributary to Prado Dam and was developed for the Santa Ana Watershed Project Authority
(SAWPA) by WEI (WEI, 2009). WEI began development of the WLAM for SAWPA in 1994 and
has improved it over time to support numerous water resources investigations.
The WLAM uses historic rainfall and stream flow along the model boundaries for the 50-year
period from 1950 to 1999. The model also accounts for the contribution of rising groundwater to
Santa Ana River flows. The volume of rising groundwater has decreased in recent years due to
lower groundwater levels in the southern portion of the Chino Groundwater Basin. Groundwater
levels in this area are expected to remain low as this is part of the basin management strategy
to reduce the migration of poor quality groundwater into the Santa Ana River.
Estimated future discharges of water from wastewater treatment plants to the Santa Ana River
are expected to decline due to conservation and increased recycling. This, along with
reductions in rising groundwater, means that projected Santa Ana River base flows reaching
Prado Dam are significantly lower than what occurred from the early 1990s to 2005.
As a result of this work, OCWD developed three Santa Ana River base flow projections:
1. High Base Flow Condition: 101,700 afy
2. Medium Base Flow Condition: 52,400 afy
3. Low Base Flow Condition: 36,000 afy
Per the 1969 Stipulated Judgment in the case of Orange County Water District v. City of Chino,
et al., Case No. 117628-County of Orange, a minimum annual Santa Ana River base flow of
42,000 afy is required to reach Prado Dam. However, a system of credits in the judgment
allows the Santa Ana River base flow to be as low as 34,000 afy until the credits are exhausted.
Given the large credit that exists due to many years of base flow exceeding 42,000 afy, the
minimum flow of 34,000 afy could be in place for many decades. Even though the minimum
allowable base flow is 34,000 afy, the annual base flow simulated was 36,000 afy due to minor
variations in rising groundwater produced by the WLAM.
In developing estimates of future Santa Ana River storm flows arriving at Prado Dam, land use
conditions in the WLAM were reviewed. For future conditions, SCAG 2005 land use data was
modified to represent future (2071) land uses. The assumptions made in modifying the 2005
land use data were: (1) already developed urban areas and surrounding mountain areas were
assumed not to change; (2) dairy, poultry, intensive livestock, as well as land use classified as
"other agriculture"were assumed to be developed; and, (3)vacant and undeveloped areas were
also assumed to be developed by 2071. In addition, all new developed land use in 2071 was
assumed to be high density residential. This analysis resulted in an increase in high density
residential area of approximately 71 square miles, a decrease dairy, poultry, horse ranch, etc.
areas by approximately 11 square miles, and a decrease in undeveloped areas by
approximately 59 square miles.
OCWD Groundwater Management Plan 2015 Update 5-22
Section 5
Management and Operation of Recharge Facilities
The increased runoff generated by future land uses is offset by plans for storm water harvesting
by upstream agencies. Plans were identified for future storm water harvesting from Seven Oaks
Dam, diversions from the Santa Ana River and its tributaries, and on-site infiltration that would
be required by the Municipal Separate Storm Sewer System (MS4) permit. To develop the
lowest flow condition possible, it was assumed that projects that have reached the
environmental review stage would be constructed. As a result, the average annual storm flow
arriving at Prado Dam is reduced by 27,360 afy (WEI, 2014b).
Future estimates of Santa Ana River storm flow arriving at Prado Dam are presented in Table 5-
4. The three Santa Ana River base flow conditions were combined with the estimated storm
flow arriving at Prado Dam to develop three inflow conditions as summarized in Table 5-5.
Table 5-4: Estimated Future Santa Ana River Storm Flow Arriving at Prado Dam
STORM FLOW RUNOFF CONDITION Average Storm Flow to
Prado Basin (afy)
Current Land Uses 118,000
Future (2071) Land Uses 125,970
Future (2071) Land Uses, Maximum Storm Water gg,610
Harvesting
Table 5-5: Santa Ana River Flow Conditions and Estimated Average Inflow to Prado Dam
Santa Ana River Flow to Prado (afy) Total
Average
CONDITION DESCRIPTION Average Base Flow Average Storm Flow Flow(afy)
High High Base Flow, Currant 101,700 118,000 219,700
Land Uses
Medium Medium Base Flow, Future 52,400 125,970 178,370
(2071) Land Uses
Low Base Flow, Future
�oW (2071) Land Uses, 36,000 98,610 134,610
Maximum Storm Water
Harvesting
5.5.4 Evaluatir�� of Potential Pr�jects t� Increase Basir� Recharge
Sixteen potential recharge projects were evaluated using the Recharge Facilities Model (RFM)
as part of the preparation of the District's Long-Term Facilities Plan 2014 Update. Key
assumptions used in the RFM are as follows:
OCWD Groundwater Management Plan 2015 Update 5-23
Section 5
Management and Operation of Recharge Facilities
1. The Prado Dam conservation pool is operating at 505 feet year round. Work to raise the
flood season pool from 498 to 505 feet is ongoing and is expected to be completed and
implemented in the next few years.
2. All GWRS water conveyed to Anaheim, including flows from the final expansion of
GWRS, will be recharged in Miraloma Basin and planned La Palma Basin. This
assumption frees up the capacity of the remainder of the recharge system for Santa Ana
River flows and imported water.
The approach to modeling each project was to compare the total system recharge with and
without the project for each flow condition. For example, total system recharge was modeled for
the high flow condition with and without a project. The difference in the recharge obtained for
the entire system comparing the two runs defined the benefit of the project being modeled. This
was then repeated for the medium and low flow conditions. Table 5-6 shows the additional yield
produced by each potential project for the high, medium, and low flow conditions.
The RFM was also used to evaluate the loss of storm flow capture that will result as sediment
continues to accumulate in the Prado Basin. Based on the historical rate of sediment
accumulation of approximately 350 acre-feet per year, the storage within the conservation pool
is projected to fill up within the next 50 years. When the conservation pool becomes filled with
sediment, the eventual loss of storm water available for recharge will range from 30,000 to
38,000 acre-feet per year.
Table 5-6: Annual Yield of Potential Surface Water Recharge System Projects based on
Recharge Facilities Model
Santa Ana River Flow Condition (afy)
PROJECT NAME
High Medium Low
Desilting Santa Ana River Flows 10 390 10
Enhanced Recharge in Santiago Creek at Grijalva Park 10 10 85
Subsurface Collection and Recharge System in Off-River 610 730 150
and Five Coves
Enhanced Recharge in Santa Ana River Befinreen Five 10 220 20
Coves/Lincoln Ave.
Enhanced Recharge in Santa Ana River Be1ow Ball Road 730 600 230
Recharge in Lower Santiago Creek 270 150 90
Five Coves Bypass Pipeline 130 10 10
Five Coves Bypass Pipeline with Lincoln Basin Rehabilitation 71p 490 100
Placentia Basin improvements 75 170 260
Raymond Basin Improvemen#s 40 230 350
River View Basin Expansion 10 100 10
OCWD Groundwater Management Plan 2015 Update 5-24
Section 5
Management and Operation of Recharge Facilities
Santa Ana River Flow Condition (afy)
PROJECT NAME
High Medium Low
Additional Wamer to Anaheim Lake Pipeline 10 10 30
Lakeview Pipeline 10 10 10
Warner System Modifications 210 250 10
Anaheim Lake Re-contouring 10 125 10
5.6 RECNARGE FA�ILITIES IMPF�t�VEMENT PRC?JECTS �ND
STUDIES 2tJ4�9-2C}14
The District regularly evaluates potential projects and conducts studies to improve the existing
recharge facilities and build new facilities. This may include: �
• Increasing the capacity to transfer water from one basin to another;
• Improving the removal of the clogging layer that forms on the bottom of basins;
� Removing shallow low-permeability silt or clay layers beneath recharge basins;
• Reconfiguring a basin to improve infiltration rates;
• Converting an underperForming basin to a new type of recharge facility; and
• Evaluating potential sites for new recharge facilities such as existing flood control
facilities and sites for construction of new basins.
Recharge improvement projects and studies completed since publication of the Groundwater
Management Plan 2009 Update include the following:
Sediment Removal Demonstration Proiects
Clogging of the District's recharge facilities is caused primarily by suspended sediments in
Santa Ana River water. To a limited extent, clogging is also caused by biological growth
supplied by the organic carbon and nutrients in the recharge water. Recharge rates achieved
when using water with little to no suspended sediment, such as imported water from the
Metropolitan Water District of Southern Califomia (MWD) and highly treated recycled water from
GWRS, are two to three times greater than what is achieved with Santa Ana River water.
In an effort to maximize the recharge of storm water, the District embarked on a multi-phased
Sediment Removal Study. Phase I of the study identified a number of sediment removal
technologies for testing. Phase II of the study included bench-scale testing of five different
treatment technologies, including:
• Flocculation-Sedimentation
• Dissolved Air Floatation (DAF)
• Ballasted Sedimentation
OCWD Groundwater Management Plan 2015 Update 5-25
Section 5
Management and Operation of Recharge Facilities
• Cloth Filtration (with and without chemical pre-treatment)
• Riverbed Filtration .
In Phase III, research continued on two of the removal technologies: Cloth Filtration without
chemical pretreatment in 2013 and Riverbed Filtration in 2014.
The Riverbed Filtration Project is located in the Off-River Channel adjacent to the main Santa
Ana River Channel. This project uses the natural treatment obtained by infiltration in native
sediments to remove suspended sediments. For this system, a large underground network of
collection pipes were installed three-to-five feet below the surFace of the Off-River channel.
Water flows by gravity into these pipes and then to Olive Basin, which has been plumbed to only
receive this filtered water. Initial results indicate that this method removes virtually all of the
suspended sediment in the water and improves water quality in ways similar to that seen in
recharge basins.
The Cloth Filter Demonstration Project is located at River View Basin. Extensive water quality
testing showed that this technology was marginally effective in reducing suspended solids
concentrations; however, it did not, as expected, affect other water quality parameters. Testing
of the cloth filter system will continue, but the scope of water quality testing has been reduced to
monitoring for turbidity and total suspended solids.
Miraloma Basin
Miraloma Basin is a new recharge basin that was placed online in 2012. OCWD acquired the
former 13-acre industrial site adjacent to existing recharge basins in Anaheim as shown in
Figure 5-15. Construction included excavation, demolition and hauling, construction of water
supply pipelines with appurtenances for
� flow control and metering, a pump
��� ��� � � station, integration with OCWD
����� .., .x
�� �-�� �° �-����� �"��' �"�° �� � "`� � supervisory control and data acquisition
„
���� � ' ���� ��'� (SCADA) system, site improvements to
�:�
�'������ s �� <��� � ,� � ��'�`��� facilitate operations and maintenance,
���: ��� �� �
as well as landscape improvements.
���,,� The new 10-acre recharge basin is
�� , � ro.� dedicated to recharge GWRS product
�°� ° � �� � ��� �� water and has capacity to recharge
.: h,� ro
��` approximately 20,000 to 30,000 afy.
,• Y .vp>,a u�^�
�
+t�„ri; a'; � �v
.�.- ^�'' iM+
�
. `", uM�-'""...�:.'.r ., ir�'r.�,.�"���a..o..A" . .. .
Figure 5-15: Miraloma Basin
Mid-Basin Injection Demonstration Project
As the GWRS is expanded, an increased supply of recharge water will be available. In order to
recharge this supply of water, the Mid-Basin Injection Project is being considered. This would
OCWD Groundwater Management Plan 2015 Update 5-26
Section 5
Management and Operation of Recharge Facilities
involve using high-quality GWRS water for direct injection into the Principal Aquifer in the central
portions of the groundwater basin. By directly injecting water into the Principal Aquifer where
most of the pumping occurs, low groundwater levels due to pumping can be reduced. Also,
mid-basin injection would reduce the recharge requirement in Anaheim and Orange area
recharge basins, thus providing more capacity to recharge Santa Ana River and imported water.
A demonstration well and two monitoring wells were constructed to evaluate the feasibility of a
full-scale injection project.
Burris and Lincoln Basins Reconfiquration
Modifications to Burris and Lincoln basins were completed to improve recharge capability. Low-
permeability sediments were excavated from Lincoln Basin and the northern end of Burris Basin
and the conveyance channel between the two basins was reconfigured.
Santiago Basins Pump Station
A floating pump station, shown in Figure 5-16, was constructed to dewater the Santiago Basins
to increase storm flow capture and
percolation, to make storage
available for winter season use, to
, ..
provide water to the Santiago
Creek for percolation, and to
increase operational flexibility by
pumping water back to Burris
Basin when necessary. Operation '
of the pump station for the basins � € �""
�`"f
increased recharge capacity and �$, "�
�
allowed for more flexible and 4''
efficient operations.
Figure 5-16: Santiago Basins Pump Station
Olive Basin Pump Station
A dewatering pump station was constructed to allow for more frequent basin cleanings and to
maintain infiltration rates. The increase in average annual recharge capacity is estimated to be
1,600 afy with maximum increase of 4,800 afy. Improvements to Olive Basin will allow the basin
to be drained more rapidly for cleaning. An intake structure with a 36-inch diameter fill pipe was
constructed to allow water to flow from the Off-River System into the deepest part of the basin.
This decreased the amount of sediment stirred up in the basin, thereby increasing the recharge
performance.
Santa Ana River Sediment Characterization Study
The Santa Ana River channel is one of the District's most productive recharge facilities,
recharging approximately 100 cubic feet per second (cfs), similar to the performance of
Anaheim Lake when freshly cleaned. The transport and deposition of sediment, primarily sand,
is important to maintaining recharge in the river bottom. However, Prado Dam traps the majority
OCWD Groundwater Management Plan 2015 Update 5-27
Section 5
Management and Operation of Recharge Facilities
of sand flowing down the river just upstream of Orange County causing changes in bed material
composition in the river downstream.
Downstream loss of sand results in coarsening of sediment and armoring. Coarsening refers to
the increase in sediment grain size, as seen in Figure 5-17, and armoring is a condition where
coarser sediments eventually interlock or harden with fine sediments and form an armored
layer. Both conditions cause a reduction in infiltration rates.
An OCWD investigation studied trends in the sediment characteristics in the river(Golder
Associates, 2009). The results highlight the importance of addressing long-term sediment
transport in the Santa Ana River. The study reached the following conclusions:
• Areas of armoring were observed in the river bed between Prado Dam and Imperial
Highway, particularly in the floodplain portion of the river outside the natural low-flow
channel.
• Below Imperial Highway, coarsening of sediment was observed but armoring was not
observed due to OCWD maintenance activities reworking sediment with earth moving
equipment.
� Continued coarsening of riverbed material and scour are expected in the river recharge
reach below Imperial Highway. Coarsening may result from: 1) entrapment of sand at
Prado Dam, 2) removal of fine material caused by moderate flows, and 2) deposition of
coarse bed material originating from the reach between Imperial Highway and Prado
Dam during high flows.
• The erosion that is expected to occur downstream of grade control and drop structures
during moderate to high flows could
result in additional deposited
coarse material concentrating in
those sections.
� • The riverbed particle
packing density is expected to
increase as the riverbed material
�:� � coarsens resulting in decreased
�-F �
"��z
� �` �� � � ����,� permeability. Additionally, there is
;� _ �-� �� ,� ����. � � ��`��. greater potential for fine-grained
�
`� �� ����"' �� �4� ��,� :��,� '���� '��"h�,�+��; sediments transported by river
� u��� ���.�► •�.��,;� �.,,� •. �. ,
�� ,� :z�,�w �� �� � � ��� �, ��. �,� .� ; ��� flows to migrate to greater depth,
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�e � �, �� ����-�� � �► � �� � � �� � � ���°* ,,� remove, causing a reduction in the
�� �� �..- g�. �� �� �.> `� -�..
�� �°��� ����,.�:� -�� ��,� ���� permeability of the riverbed
� �� � �. ��.
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Figure 5-17: Sand and Cobble Sediments in Santa Ana River Channel
OCWD Groundwater Management Plan 2015 Update 5-28
GROUNDWATER REPLENISHMENT
SYSTEM �
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� � GWRS�Water Pump Station and RO Electrical Building
The Groundwater Replenishment System began operation in 2008.
Overview
• Produces up to 100 million gallons per day
• Recycled water used for groundwater recharge and seawater barrier operations
Treatment Process
• Microfiltration
• Reverse osmosis
• Ultraviolet light with hydrogen peroxide
Water Quality Monitorinq
• Independent Advisory Panel evaluates monitoring programs
• Network of monitoring wells used to track travel times from recharge sites to
production wells
Section 6
Groundwater Replenishment System
� �T� �� �Q� T P'L��� T
� �
6.1 C�OlERV6�W
The Groundwater Replenishment System (GWRS) is a joint project built by OCWD and the
Orange County Sanitation District (OCSD) that began operating in 2008 (see Figure 6-1).
Wastewater that otherwise would be discharged to the Pacific Ocean is purified using a three-
step advanced process to produce high-quality water used to control seawater intrusion and
recharge the Orange County Groundwater Basin. The GWRS produces up to 100 million
gallons per day (mgd) of highly-treated recycled water. The system includes three major
components (1)the Advanced Water Purification Facility (AWPF), (2)the Talbert Seawater
Intrusion Barrier and (3) recharge basins where GWRS water is percolated into the groundwater
basin, schematically illustrated in Figure 6-2.
Secondary-treated wastewater is conveyed to OCWD from OCSD Plant No.1, located adjacent
to the District's facilities in Fountain Valley. The water undergoes an advanced treatment
process that includes microfiltration, reverse osmosis and advanced oxidation/disinfection with
hydrogen peroxide and ultraviolet light exposure followed by de-carbonation and lime
stabilization. The Full Advanced Treated (FAT)water is used for groundwater recharge, to
supply the Talbert Seawater Barrier and provide recycled water for three industrial/commercial
users. The AWPF produces up to 100 mgd or approximately 112,000 afy. Approximately 34%
of the water is injected in the Talbert Barrier and 66°/a is percolated in the recharge basins.
Industrial and commercial uses include cooling water for the City of Anaheim's Canyon Power
Plant, recycled water for the Anaheim Regional Transportation Intermodal Center, and
hydrostatic testing of new secondary treatment basins at OCSD Plant No.1.
The Talbert Seawater Intrusion Barrier consists of a series of 36 injection well sites that are
supplied by pipelines from AWPF. OCWD constructed the injection barrier to form an
underground hydraulic mound, or pressure ridge, to manage seawater intrusion near the coast
in the Talbert Gap area. The Talbert Barrier wells also serve to replenish the groundwater basin
with injection of purified, recycled water into the Main Aquifer.
In addition to supplying the Talbert Barrier, GWRS water is recharged in Kraemer, Miller and
Miraloma basins, located in the city of Anaheim. Water is conveyed to these basins through a
13-mile pipeline in the west levee of the Santa Ana River through the cities of Fountain Valley,
Santa Ana, Orange, and Anaheim and along the Carbon Canyon Diversion Channel. Five feet in
diameter at its end point, this pipeline is capable of delivering over 80 million gallons of highly-
treated recycled water to the basins each day.
OCWD Groundwater Management Plan 2015 Update 6-1
Section 6
Groundwater Replenishment System
.
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Figure 6-1: Aerial View of the Groundwater Replenishment System
OCWD Groundwater Management Plan 2015 Update 6-2
Section 6
Groundwater Replenishment System
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Figure 6-2: Groundwater Replenishment System Facilities
6_1 .1 Nistory
The need for a reliable water supply for the Talbert Barrier led to the construction of Water
Factory 21 (WF 21) in 1975. This 15-mgd advanced water purification plant treated secondary
treated wastewater from OCSD with lime clarification, ammonia stripping, re-carbonation,
multimedia filtration, granular activated carbon (GAC) adsorption, and chlorination. A 5-mgd
reverse osmosis (RO) demineralization plant was added to the process in 1977 to reduce total
dissolved solids in the product water.
OCWD Groundwater Management Plan 2015 Update 6-3
Section 6
Groundwater Replenishment System
WF 21 was the first plant in the world to use RO to purify wastewater to drinking water
standards. The GAC-treated water and RO-treated water were blended with groundwater and
imported water to supply the injection wells and recharge the groundwater basin. Due to new
water quality issues in 2000, WF-21 subsequently used only RO-treated water.
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Figure 6-3: Water Factory 21, circa 1975
By the mid-1990s, OCWD needed a larger supply of water to manage seawater intrusion. Plans
to build the GWRS plant coincided with OCSD's need to build a second ocean outFall to dispose
of increased wastewater flows. Expanding the advanced water treatment plant, therefore,
would not only increase water supplies for OCWD but would also reduce the volume of
secondary-treated wastewater and provide an alternative to a second ocean outfall.
The original WF 21 ceased operations in 2004. At that time Interim Water Factory 21 (IWF 21)
operated for two years while the GWRS was being built. In addition to continuing the seawater
intrusion prevention effort, IWF 21 served as a training facility, enabling staff to become familiar
with the treatment processes being developed for the GWRS facility. Plant modifications
included the addition of microfiltration and low-pressure high-intensity ultraviolet light with
hydrogen peroxide to create an advanced oxidation process. The new processes, together with
the existing RO system retrofitted with thin film composite polyamide membranes, resulted in
increased energy efficiency and more effective removal of contaminants. The addition of
hydrogen peroxide upstream of the UV light enhanced the oxidation process and enabled the
destruction of UV-resistant contaminants. In the interim between IWF 21 taken off-line until
completion of GWRS in 2008, OCWD used potable water from imported sources and the City of
Fountain Valley for barrier operations.
OCWD Groundwater Management Plan 2015 Update 6-4
Section 6
Groundwater Replenishment System
6.2 ADV�N��D WATER TREATMENT PR{7CE�S
The advanced water treatment process consists of microfiltration, reverse osmosis and
ultraviolet light with hydrogen peroxide and lime treatment. This process is illustrated in Figure
6-4 and explained in more detail below.
MF qeaNrp Campracaed SadWm
. Syslem Air Hypodiake
.. ^.�'��..:<f
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OCSD
Plant No.1
Rp Bypass
Decarbonator Reverse Osmosis RO Fluah
To sys�am
� Barrler �� P. .,: .,
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Pump RO�Flush Tank Nydroxide
Station To OCSD Ocean OuffaU
SodWm
Ume BisWMe ��. .,
To Peak Flow and Eme enc 9 ss
Santa Ana
Rlver
Figure 6-4: AWPF Process Flow Diagram
6.2.1 Microfiltr�tron
Secondary-treated wastewater from the OCSD wastewater treatment plant is gravity-fed to
OCWD. The effluent is fine-screened at the AWPF influent screening facility and then passes
through the microfiltration (MF) process. Bundles of hollow polypropylene fibers in submerged
racks remove particulate contaminants from water. Under a vacuum, water is drawn through the
fibers' minute pores, each approximately 0.2 microns in diameter; suspended solids, protozoa,
bacteria, and some viruses are strained out. The MF cells are regularly backwashed to clean
the membranes. The MF membranes are periodically cleaned-in-place using citric acid and
sodium hydroxide with a proprietary chemical to remove foulants and restore membrane
performance. Waste backwash and cleaning solutions are returned to OCSD for treatment.
6.2.2 (�everse Qsmasis
The MF product water advances to the next step in the process, reverse osmosis (Ra). This
system uses envelopes of semi-permeable polyamide membranes rolled into bundles and
OCWD Groundwater Management Plan 2015 Update 6-5
Section 6
Groundwater Replenishment System
encased in long pressure vessels. Pressurized micro-filtered water enters at one end of each
vessel and passes through the membrane to the inside of the envelope where purified product
water is collected, exiting through the product water pipes.
The RO process demineralizes water and removes inorganics, organics, viruses and other
contaminants. The RO process features pretreatment chemical addition using sulfuric acid and
anti-scalant, cartridge filtration and high pressure feed pumps that supply the pressure vessels
containing the RO membranes. Concentrate from the RO process is discharged to OCSD for
disposal.
f3.�,3 Ultraviolet Lig�t w�th Hydro�en PerUxid� and Lime Treatment
After purification with MF/RO, water is exposed to high intensity ultraviolet light (UV) and treated
with hydrogen peroxide (H2O2)to disinfect the water and destroy remaining low molecular
weight organic compounds including those that must be removed to parts per trillion levels. This
process ensures that unwanted biological materials and organic chemical compounds are
effectively destroyed or removed.
Post-treatment consists of de-carbonation and lime stabilization to raise the pH and add
hardness and alkalinity to make the recycled water less corrosive and more stable. Excess
residual carbon dioxide is removed from the RO permeate by five forced-draft decarbonators in
order to stabilize the finished product water. The de-carbonation system treats about 80% of
the UV disinfected recycled water while the remaining flow bypasses the decarbonators.
Hydrated lime (calcium hydroxide) is added to neutralize the remaining carbon dioxide and
stabilize the finished product water.
6.3 ENERGY EFFICIENT OPERATIONS
When designing and building the District's GWRS, the conservation of energy was established
as a priority. Energy efficiency was built into the original GWRS plant design.
The District participated in Southern California Edison's "Efficiency by Design" grant funding
program. Selection of energy efficient elements enabled OCWD to take advantage of grant
funds to purchase capital equipment and realize the long-term benefits of reducing the energy
load for day-to-day plant operations.
The reverse osmosis facility was designed and built with energy recovery devices that capture
energy normally lost when water is released through a throttling valve from a high pressure
system. It is expected that the high-tech energy recovery system will save 14 million kW hours
and $ 1.3 million dollars every year for the life of the system. Another benefit of this device is its
corresponding reduction in greenhouse gas emissions of 14 million pounds per year. The use
of new technology energy recovery units (ERDs) in the expanded reverse osmosis system was
designed to produce a significant and long-term savings in pumping costs. The ultraviolet (UV)
OCWD Groundwater Management Plan 2015 Update 6-6
Section 6
Groundwater Replenishment System
advanced oxidation system was also selected, in part, because of its optimal energy
performance characteristics.
In addition to these devices, the GWRS uses variable frequency drives on virtually all of its
pumps and other rotating equipment. These computer controlled devices vary the rotational
speed of the motors allowing for flow control and improved energy efficiency. Reduction in
energy use for lighting is achieved by the widespread uses of skylights and open-air designs as
well as new low-power designs.
The District participates in the demand response program. OCWD agrees to curtain plant
operations during times of grid emergency or insufficient generation, which provides the
equivalent of 11 megawatts of increased peak generation for the regional electrical system. In
addition, pumping operations are shifted, when possible, to off-peak times (usually at night)to
relax demand on the system during peak loads.
�.4 PLA T t�F'TIl�10ZAT1(�N AND EXPANSIC�N
During FY 2012-2013, GWRS achieved the highest production since start-up in January 2008
with 72,691 acre-feet of FAT water produced. In contrast, during the first year of operation, the
plant produced 43,500 acre-feet of recycled water. Increased production was made possible by
a number of operational improvements and construction of additional facilities, as described
below.
Steve Anderson Lift Station
OCSD constructed Steve Anderson Lift Station in 2009 to provide additional flow to the GWRS.
The lift station diverts up to 50 mgd of raw wastewater from OCSD Plant 2 to OCSD Plant 1,
boosting the amount of secondary effluent that could be conveyed to the GWRS for treatment.
Microfiltration Backwash StoraQe
The AWPF was designed to treat a relatively constant flow rate, but flows to the wastewater
treatment plant experience low nighttime flows. To help with the diurnal flow deficit, OCWD and
OCSD completed a project in 2012 to store MF backwash waste generated by the GWRS in
existing OCSD's primary clarifies that are otherwise unused. MF backwash waste is stored
during the day in the primary basins and pumped back into the secondary process during the
low diurnal flow period at night using 10 sump pumps. These pumps are scheduled to come on
at various intervals at the start of the flow deficit and are secured when OCSD's flows begin to
recover in the morning. The project has helped make up about 2.4 mgd during the diurnal feed
water flow deficit and has enabled the AWPF to produce closer to the design capacity.
Addition of Microfiltration Cells
The capacity of the MF process was increased in 2011 with the buildout of the existing 26 MF
cells that contained 608 MF membranes with an additional 76 membranes for a total of 684 MF
membranes per MF cell. This provides additional flexibility and capacity to maintain production `
OCWD Groundwater Management Plan 2015 Update 6-7
Section 6
Groundwater Replenishment System
when MF cells are down for cleaning or repairs, increasing available MF productian capacity
from 86 to 102.4 mgd at 89% recovery.
Optimization of the RO Process
Throughout 2012, research was conducted to optimize operations of the RO process through
management of both biological and mineral membrane fouling. A variety of experimental
laboratory cleanings were conducted to assess the effectiveness of removing mineral foulant
from membranes. Experimental cleaning was performed on membrane samples and the
effectiveness of cleaners in removing foulant from the membrane surFace and restoring
permeability was evaluated.
Plant Expansion
Construction of the initial expansion of GWRS was completed in 2015. This provides an
additional 30 mgd of capacity and includes construction of flow equalization facilities to
,? compensate for diurnal fluctuation in secondary treated source water from Plant No.1. The
initial expansion increases total plant capacity to 100 mgd. Plans are being drawn up to
construct the final expansion of GWRS, which would increase total capacity to 130 mgd.
GWRS Flow Equalization Tanks
Two 7.5 million gallon storage tanks (Figure 6-5) were constructed by OCWD on land owned by
OCSD in Fountain Valley to provide storage of secondary-treated wastewater on a temporary
basis during daily peak flow periods prior to conveyance to OCWD for advanced treatment at
GWRS. Due to diurnal flow patterns of wastewater at the OCSD plant, daytime flow to the
GWRS plant exceeds plant capacity while nighttime low flows result in the plant operating at
below capacity. Excess flows bypass the GWRS and are discharged to the Pacific Ocean via
the OCSD ocean outfall pipeline. The Flow Equalization Tanks will store wastewater when
flows exceed the GWRS plant capacity and will be conveyed to the plant at night when flows
drop to levels below plant capacity.
;�s;
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Figure 6-5: Flow Equalization Tanks
OCWD Groundwater Management Plan 2015 Update 6-8
Section 6
Groundwater Replenishment System
6.� W�TER t�lJAL1T`� �C�NIT(J�I G I�ND REPC)RT16V�
OCWD's extensive nefinrork of monitoring wells within the groundwater basin includes
concentrated monitoring along the seawater barrier and near the recharge basins. GWRS-
related monitoring wells in the vicinity of Kraemer, Miller, and Miraloma basins are used to
measure water levels and to collect water quality samples. In addition to ensuring the protection
of water quality, these wells are used to determine travel times from recharge basins to
production wells. Monitoring programs related to operation of GWRS are described in detail in
Section 4.
Because of the long history of using advanced purified water at the Talbert Barrier, OCWD is
permitted to use 100% GWRS water for injection into the barrier without blending with imported
water or other sources as required for other seawater barrier projects in Southern California.
However, blending is still required at the recharge basins with GWRS water making up no more
than 75% of the blend with the balance coming from Santa Ana River storm flows and imported
water.
Permits regulating operation of GWRS require adherence to rigorous product water quality
specifications, extensive groundwater monitoring, buffer zones near recharge operations,
reporting requirements, and a detailed treatment plant operation, maintenance and monitoring
program.
fi.5.1 Th� Indep�ndent Ad�i�c�ry PaneC
Performance of the GWRS plant is monitored by OCWD's research department and the
Advanced Water Quality Laboratory. Annual GWRS reports are prepared by a diplomate of the
American Academy of Environmental Engineering and an Independent Advisory Panel (IAP)to
document ongoing scientific peer review. The IAP analyzes data in OCWD's Annual GWRS
Report of plant operations as well as water quality data collected throughout the groundwater
basin. The IAP is appointed and administered by the National Water Research Institute to
provide credible, objective review of all aspects of GWRS by scientific and engineering experts.
In addition to formal written reports, the IAP also offers suggestions for enhancing monitoring of
water quality, improving the efficiency of current GWRS technologies and evaluating future
projects associated with the GWRS.
6.5.2 GWR� �4nnual Reper�fi
A GWRS Annual Report is prepared in fulfillment of the requirements specified in the permit
issued by the Santa Ana Regional Water Quality Control Board in 2008.' The order specifies
� Producer/User Water Recycling Requirements and Monitoring and Reporting program for the Orange
County Water District Interim Water Factory 21 and Groundwater Replenishment System Groundwater
Recharge and Reuse at Ta/bert Gap Seawater Intrusion Barrier and Kraemer/Miller Basins adopted as
Order No. R8-2004-0002, Santa Ana Regional Water Quality Control Board on March 12, 2004 and the
subsequent amendment Order No. R8-2008-0058 adopted on July 18, 2008.
OCIJVD Groundwater Management Plan 2015 Update 6-9
Section 6
Groundwater Replenishment System
permit requirements for the GWRS for purified recycled water for industrial uses and at the
Talbert Barrier and recharge basins. The annual report contains a detailed evaluation of the
operation of the entire GWRS and creates a historical record of operations of the water
reclamation as well as groundwater recharge and reuse facilities.
�.6 PU�LIC 4tJTR�A�N
Since the GWRS came on-line in January 2008, more than 24,000 visitors have toured the
facility. During FY 2013-14, OCWD conducted 198 public tours of the GWRS plant and the
Advanced Water Quality Laboratory with a total of 3,432 participants. Tour groups included 10
local high schools and 20 colleges and universities. In addition to many groups from throughout
the United States, OCWD hosted tours from China, Korea, Japan, Saudi Arabia, Thailand,
Australia, Switzerland, and Russia.
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OCWD Groundwater Management Plan 2015 Update 6-10
SEAWATER INTRUSION AND BARRIER
MANAGEMENT
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Background
• Coastal gaps most susceptible to seawater intrusion
• Construction of barriers began in 1960s
Talbert Seawater Intrusion Barrier
• 36 well sites used to inject fresh water into 4 aquifer zones
• GWRS recycled water used for barrier operation
Alamitos Seawater Intrusion Barrier
• Joint operation since 1964 with Los Angeles County Flood Control District
• 43 injection well and 177 active monitoring sites
• Expansion of barrier under investigation
Sunset Gaq Investigation
• Elevated chloride levels indicate seawater intruding through gap
• Investigation underway to evaluate altemative remedies
Section 7
Seawater Intrusion and Barrier Management
���Tld� 7 ��A T�ER INT U T AND BARRI�R
I� T
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In the coastal area of Orange County, the primary source of saline groundwater is seawater
intrusion into the groundwater basin through permeable sediments underlying topographic
lowlands or gaps between the erosional remnants or mesas of the Newport-Inglewood Uplift. �
The susceptible locations are the Talbert, Bolsa, Sunset, and Alamitos Gaps as shown in Figure
7-1.
Seawater intrusion became a critical problem in the 1950s. Overdraft of the basin caused water
levels to drop as much as 40 feet below sea level; seawater intruded over three miles inland.
Prior to the construction of the seawater intrusion barriers, OCWD slowed seawater intrusion by
filling the basin with
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Figure 7-1: Coastal Gaps in Orange County
OCWD Groundwater Management Plan 2015 Update 7-1
Section 7
Seawater Intrusion and Barrier Management
In July 2014, the District's Board of Directors adopted a policy regarding control of seawater
intrusion that contained the following principles:
• Prevent degradation of the quality of the groundwater basin from seawater intrusion.
• Effectively operate and evaluate the performance of the District's seawater barrier
facilities.
• Adequately identify and track trends in seawater intrusion in susceptible coastal
areas and evaluate and act upon this information, as needed, to protect the
groundwater basin.
In addition to the seawater barrier injection facilities, the District operates and maintains a
network of coastal area monitoring wells that provide water level and water quality data that
allow staff to evaluate the performance of the barriers and to identify potential areas of intrusion.
OCWD measures chloride concentrations in groundwater to monitor seawater intrusion.
Chloride concentrations are monitored twice a year at the coastal area monitoring wells and
chloride contour maps are prepared at least every two years to delineate the extent of seawater
intrusion and determine areas where it is migrating inland or being pushed seaward. The
monitoring well network has been expanded and improved over time leading to new information
and a greater understanding of the coastal hydrogeology and intrusion pathways. A more
� detailed discussion of the coastal water quality monitoring program can be found in Section 4.
The Alamitos and Talbert Seawater Intrusion Barriers control seawater intrusion through the
Alamitos and Talbert Gaps by injecting fresh water into susceptible aquifers through a series of
wells. The pressure mound resulting from this injection minimizes seawater intrusion through
these gaps into the basin. The District plans to expand the Alamitos Barrier with additional
monitoring and injection wells and is currently expanding the monitoring well network in Sunset
Gap to better delineate the nature and extent of seawater intrusion in that area as the first step
towards investigating feasible remedies for Sunset Gap. In Bolsa Gap, chloride concentration
trends suggest that the Newport-Inglewood Fault System sufficiently restricts inland migration of
seawater intrusion into the potable aquifers.
7.2 TALB�RT S�AVit�T�R I�1TRU�IQN BARRIER
Seawater intrusion through the Talbert Gap, a 2.5-mile-wide geological feature between the
Newport and Huntington Beach mesas, was documented as far back as 1925. A more detailed
study of the gap was conducted by the Department of Water Resources in 1966 (DWR, 1966).
Largely based on this study, OCWD constructed the initial Talbert Seawater Intrusion Barrier in
1975 with 23 injection well sites.
Over time the barrier was expanded to keep pace with increasing groundwater production in the
coastal area. Chloride concentrations at OCWD monitoring wells in the 1990s showed
advancing seawater intrusion in the Talbert Gap and beneath the adjacent mesas despite
barrier injection operations. Today, the Talbert Barrier is composed of a series of 36 well sites
that are used to inject water into multiple aquifer zones for seawater intrusion control as well as
basin replenishment. The injection raises groundwater levels along the barrier alignment and �
OCWD Groundwater Management Plan 2015 Update 7-2
Section 7
Seawater Intrusion and Barrier Management
thus forms a hydraulic barrier to seawater that would otherwise migrate inland toward areas of
groundwater production. A list of the injection wells, injection depths, and associated aquifers
can be found in Appendix E. Injection well sites are shown in Figure 7-2.
From 1975 until 2008, a blend of deep well water, imported water and recycled water from the
former Water Factory 21 was injected into the barrier. In 2008, GWRS recycled water became
the primary supply used for the injection wells, with a small and intermittent portion of the supply
from potable imported water delivered via the City of Huntington Beach at the OC-44 turnout
and potable water delivered by the City of Fountain Valley (a blend of groundwater and imported
water). A permit issued by the Santa Ana Regional Water Quality Control Board in 2004 limited
the percentage of recycled water at the Talbert Barrier to 75% with a minimum travel time of six
months to the nearest production wells. The permitted maximum allowable recycled water
contribution at the Talbert Barrier was subsequently increased to 100% in December 2009. (CA
RWQCB, 2004, 2008)
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Figure 7-2: Talbert Barrier Injection Wells
The chloride concentration contours for the Talbert Gap and surrounding area shown in Figure
7-3 illustrate historical inland progression and seaward reversals of groundwater salinity due to
injection operations and basin management practices. In addition to contour maps, OCWD staff
prepares and reviews chloride concentration trend graphs at individual wells to identify and
evaluate intrusion in specific aquifer zones over time.
In general terms, chloride concentrations are inversely related to groundwater elevations. When
groundwater elevations decline below mean sea level in the area of the intrusion front, chloride
concentrations generally increase and seawater intrusion worsens (see Figure 7-4).
OCWD Groundwater Management Plan 2015 Update 7-3
Section 7
Seawater Intrusion and Barrier Management
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Figure 7-3: Talbert Gap 250 mg/L Chloride Concentration Contours for Selected Years
Conversely, when groundwater elevations rise and are sustained above mean sea level,
chloride concentrations decrease and intrusion is pushed back seaward. This is especially
evident in Figure 7-5 which shows how chloride concentrations were significantly reduced when
new injection wells were turned on to raise groundwater levels.
Monitoring well OCWD-M26 is strategically located seaward of the barrier in the Talbert-Lambda
mergence zone in the middle of the Talbert Gap and is screened in both the Talbert and
Lambda aquifers. Therefore, OCWD-M26 is a key monitoring well for evaluating barrier
injection requirements versus seawater intrusion potential. OCWD-M26 is located
approximately 1,000 feet north of Adams Avenue, which approximately represents the farthest
seaward line at which the goal is to achieve protective groundwater elevations of approximately
3 feet above mean sea level (ft msl).
This protective elevation is based on the Ghyben-Herzberg relation (Ghyben, 1888; Herzberg,
1901; Freeze and Cherry, 1979), which takes into account the depth of the Talbert aquifer at
that location along with the density difference between saline and fresh groundwater. If this
protective elevation is achieved along Adams Avenue for at least the majority of each year, then
brackish water in the Talbert aquifer would be maintained slightly seaward of the mergence
zone and thus prevented from migrating down into the Lambda aquifer that is tapped by inland
production wells.
OCWD Groundwater Management Plan 2015 Update 7-4
Section 7
Seawater Intrusion and Barrier Management
OCWD operates the Talbert Seawater Intrusion Barrier to (1) maintain protective groundwater
elevation at well OCWD-M26 and (2) prevent landward seawater migration into the groundwater
basin based on the 250 mg/L chloride concentration contour. For more detailed information on
the operation of the Talbert Seawater Barrier see GWRS 2013 Annua/Report prepared for the
California Regional Water Quality Control Board, Santa Ana Region, June 16, 2014.
4,000 , 20
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Figure 7-4: Groundwater Elevations and Chloride Concentrations at OCWD-M27
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Figure 7-5: Groundwater Elevations and Chloride Concentrations at HBM-2/MP1
OCWD Groundwater Management Plan 2015 Update `� 7-5
Section 7
Seawater Intrusion and Barrier Management
7.3 AL� �T�S SEAWAT�R iNT�U�I�N E3AoRf�IER
The Alamitos Seawater Intrusion Barrier was constructed in 1965 to protect the Central Basin of
Los Angeles County and the Orange County Groundwater Basin from seawater intrusion
through the Alamitos Gap. Since the barrier alignment lies in both Los Angeles and Orange
Counties, the barrier facilities are jointly owned by the Los Angeles County Flood Control District
(LACFCD) and OCWD and include 43 injection wells and 177 active monitoring well sites.
Under the terms of a 1964 joint agreement, LACFCD operates and maintains the barrier, while
the Water Replenishment District of Southern California (WRD) and OCWD purchase and
provide the injection water supply, which currently consists of nearly 100% recycled water.
WRD is under permit with the Regional Water Quality Control Board — Los Angeles Region
(LARWQCB)for injection of recycled water at the Alamitos Barrier. LARWQCB permit
requirements include groundwater monitoring and numerical modeling to track the recycled
injection water migrating towards nearby municipal production wells in Orange County.
A list of the injection wells, injection depths and associated aquifers for wells on the Orange
County side of the barrier can be found in Appendix E. All injection well sites are shown in
Figure 7-6. Although OCWD owns many of the Alamitos Barrier monitoring and injection wells,
all of the wells are operated, maintained and sampled by LACFCD as part of the Alamitos
Barrier joint agreement described above.
OCWD funds operation of the Alamitos Seawater Intrusion Barrier with the Los Angeles County
agencies to prevent landward seawater migration into the groundwater basin based on the 250
mg/L chloride concentration contour.
Over the last several years, pockets of elevated chloride concentrations have been observed
inland of the barrier, especially near the southeast portion of the barrier within Orange County.
Elevated chloride concentration is the parameter that the District uses to determine if the barrier
is sufficiently protecting seawater intrusion from occurring. In this case, OCWD began a study to
delineate the extent of seawater intrusion both through and around the Alamitos Barrier as
summarized below.
• In 2008, OCWD identified critical data gaps where seawater intrusion was suspected but
unconfirmed.
• Four monitoring wells were installed in 2009 at three sites near the Orange County
portion of the barrier. As shown in Figure 7-6, salinity data from existing and the newly-
installed wells were used to delineate the extent of seawater intrusion in this area,
especially pertaining to potential migration towards nearby production wells owned and
operated by the City of Seal Beach and Golden State Water Company.
• A pipeline hydraulic model of the Alamitos Barrier injection system was completed in
2009 to determine injection supply pipeline capacities under existing conditions and for
potential barrier expansion alternatives.
OCWD Groundwater Management Plan 2015 Update 7-6
Section 7
Seawater Intrusion and Barrier Management
• Groundwater level and salinity data from the new and existing monitoring wells were
evaluated, in conjunction with the development and calibration of a detailed numerical
groundwater flow and transport model of the Alamitos Gap area (Intera, 2010). The
three agencies (OCWD, LACFCD and WRD) collaborated to develop the Alamitos
Barrier Flow Model (ABFM) and Alamitos Barrier Transport Model (ABTM). The models,
completed in 2013, simulate the fate and residence time of recycled water used for
injection and the relative differences in chloride transport and barrier performance for the
existing Alamitos Barrier and three selected barrier expansion configurations. As
explained earlier, the models were used to assess and plan for necessary expansion of
barrier facilities, as well as prioritize and optimize operation of the existing facilities to
combat against seawater intrusion.
A future southern extension of the barrier is being investigated to halt the eastem migration of
saline water into the Sunset Gap.
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OCWD Groundwater Management Plan 2015 Update 7-7
Section 7
Seawater Intrusion and Barrier Management
7.4 SUf�SET �AF' INVESTIGATl4�N
Basin monitoring for potential seawater intrusion in the vicinity of the Sunset Gap began in the
1950s. While the Newport-Inglewood Fault acts as the primary coastal barrier to seawater
intrusion into the groundwater basin, investigations between 1959 and 1983 indicated the
potential for saline water leakage across the fault, particularly in shallow aquifers and when
inland groundwater levels are significantly below sea level due to pumping and decreases in
groundwater storage.
The dredging of Huntington Harbor in the early 1960s was the subject of several studies
regarding the potential for worsening saline intrusion in this area and the influence of tides on
seawater intrusion. Conclusions of the studies as to Huntington Harbor's effect on saline
intrusion were inconsistent. Studies done by DWR (1968) and USGS (1966)found that
seawater intrusion into the semi-perched aquifer(generally the uppermost 50 feet) associated
with the harbor development was occurring, but this was considered to be of little to no
significance due to the lack of beneficial use of this near-surface water bearing zone.
In 2007, the City of Huntington Beach Well No. 12 was permanently removed from service due
to high salinity levels. In response, the District commissioned an electric geophysical survey in
2010 to delineate the extent and magnitude of seawater intrusion in the Sunset Gap. In 2012,
two multi-depth monitoring wells, OCWD-BS10 (BS10) and OCWD-BS11 (BS11)were installed
as shown in Figure 7-7 to better delineate the extent and source of the seawater intrusion.
Elevated chloride concentrations were found at both wells at a depth of approximately 230 feet,
confirming seawater intrusion. Suspected pathways are from the Alamitos Gap to the west,
Huntington Harbor to the south and possible leakage across the Newport-Inglewood Fault to the
southwest. Construction of six multi-depth nested monitoring well sites (a total of 29 individual
well casings to depths up to 1,000 feet) is underway to further delineate the extent and sources
of the seawater intrusion in Sunset Gap, and to support a future feasibility study of alternatives
to control the seawater intrusion. By early 2015, four of the six new monitoring well sites were
constructed on the Naval Weapons Station Seal Beach as shown in Figure 7-7 (BS14, BS17,
BS21, and BS22).
Strategies to control intrusion under consideration include a potential southerly extension of the
Alamitos Seawater Barrier along Seal Beach Boulevard and a brackish groundwater extraction
and desalination system. Such a system may be necessary and appropriate to prevent a large
"plume" of elevated salinity to continue to migrate toward production wells and impact larger
portions of the groundwater basin.
OCWD Groundwater Management Pian 2015 Update 7-8
Section 7
Seawater Intrusion and Barrier Management
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�1.5 EVALUATEC}N OF POTER�TIP�L IMF'A�TS DUE TO CLIMATE
CHANGE
The U.S. Bureau of Reclamation conducted a study in collaboration with SAWPA of the
potential impacts to water resources due to climate change in the Santa Ana River Watershed.
(USBR, 2013) The purpose of the study was to refine the watershed's water projections and
identify potential adaptation strategies in light of projected efFects of climate change. The study
included the development of hydrology models and analysis of impacts focused on key areas.
Likely impacts of changing climatic conditions in the Santa Ana River Watershed include a
decrease of surface water supplies, increase in temperatures, more severe flood events, and
increase dependency on groundwater supplies.
OCWD Groundwater Management Plan 2015 Update 7-9
Section 7
Seawater Intrusion and Barrier IVlanagement
Results of the study indicate that increasing temperatures will melt ice sheets and glaciers and
cause thermal expansion of ocean water, increasing the volume of water in the oceans and
raising sea levels. Regional mean sea level along the Southem California coast is projected to
rise by 1.5 to 12 inches by 2030, 5 to 24 inches by 2050, and 16 to 66 inches by 2100. Regional
sea level rise may be higher or lower than global mean sea level rise due to regional changes in
atmospheric and ocean circulation patterns.
Sea level rise is likely to increase the coastal area vulnerable to flooding during storm events.
OCWD conducted a study to evaluate the potential effects of projected sea level rise on coastal
Orange County groundwater conditions. Two locations were selected for analysis near the
Talbert and Alamitos seawater intrusion injection barriers. The study model used data from well
logs, aquifer pump tests, groundwater elevation measurements, hand-drawn contour maps,
geologic cross sections, water budget spreadsheets and other data stored in OCWD's Water
Resources Management System database.
The Talbert Barrier would be effective at preventing seawater intrusion though the Talbert Gap
under the condition of a 3-foot rise in sea level. In the case of the Alamitos Barrier, seawater
intrusion throughout the gap would likely be prevented once current plans to construct additional
injection wells are implemented. At both barriers, however, shallow groundwater concerns
could limit injection rates and thus reduce the effectiveness of the barriers in preventing
seawater intrusion under rising sea levels.
The groundwater screening tool was used to estimate changes in basin-average groundwater
levels over time as a function of seven natural and anthropogenic factors that govern
groundwater recharge and discharge: precipitation, local stream flow, trans-basin water
imports, municipal and industrial water demands, agricultural water demand, evaporative
demand from native and landscaped vegetation, and an optional exogenous input that
represents groundwater management objectives that affect basin-scale groundwater levels.
OCWD Groundwater Management Plan 2015 Update 7-10