Update on Sustainable
Water Master Plan
9/22/2026
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September 22, 2026
Regional Water Supply Outlook
Colorado River
State Water Project
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Diverse, sustainable, & drought
resilient water supply to support a
sustainable community
Energy footprint reduction to
support carbon reduction goals for
the City
Long term cost benefits for rate
payers
Goals of the City’s Sustainable Water Master Plan
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Charnock
Arcadia WTP
Potable Water Wastewater To City of
Los Angeles
Olympic Well Field
Restoration
Clean Beaches
SWIP Initiative Tank
AWTF + SMURRF
Recycled
Water
Component 1
Conservation
Component 2
Alternative Water Supply
Component 3
New Local
Groundwater
2018 Sustainable Water Master Plan (SWMP)
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Recap of 2018 SWMP Implementation
5 • Implementation impacted by COVID-19 pandemic and geopolitical events • Majority of 2018 SWMP completed in 2025
• Estimated Local Water Supply Production = 80-85% local, new baseline in FY26/27 • Component 1 – Water Conservation
• Maintained status quo due to COVID-19 restructuring
• 2024 Water Conservation Master Plan
• Component 2 – Alternative Water Supply
• Sustainable Water Infrastructure Project Completed in December 2022 • Arcadia WTP Production Efficiency Enhancement Completed in June 2025 • Extension of recycled water network and 2nd groundwater recharge well delayed • Component 3 – New Local Water Groundwater
• Olympic Wells SM-8 and SM-9 Completed in 2022
• Olympic Well Field Restoration Project Completed in June 2025 • Other Projects:
• AMI Smart Water Meter
• Charnock Well 13 and 18 Replacement (Fall 2026)
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6 SWIP Advanced Water Treatment Facility
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7 First Municipal Flow Reversal RO in the World
• Producing more drinking water
with the same amount of
groundwater pumped
• Increase RO recovery to ≥90%
• Maximize use of existing assets
• Reduce specific energy
consumption by almost 10%
• Operation flexibility
• Lower operation and life-cycle
cost while increasing drinking
water production
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Advanced Water Metering Infrastructure (AMI)
Deployment Across the City
24% 23% 22% 13% 10% 8%
Capital
Improvement
Projects
Labor
• Customers Can Access Their Water Usage
Information in Real Time
• Help Customers Budget Their Utility Bill
• Water Leak Alerts
Leak detected
https://www.santamonica.gov/ami
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Things that We Learned Along the Way
9 • Sustainable Groundwater Management
• Sustainable yield and water budget
• Production/relaxation of groundwater wells -
unable to sustain 100% capacity and 24/7
operation of each well
• Limited groundwater recharge capacity
• Impact of peak day/week water demand
– local production unable to keep up
• Emergency preparedness –
regional wildfire response
• Regulations
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Objective of 2026 One Water Master Plan
10 • Update 2018 SWMP to recalibrate water supply and demand analysis (e.g., water supply gap for water self-sufficiency)
• Identify near-term and long-term local water supply opportunities to close the gap • Evaluate and recommend near-term and long-term water supply programs • Position for outside funding to implement near-term opportunities Item 7-A
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Water Supply Gap Analysis
Up to 4,500 AF gap
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Local Water Supply Alternatives
12 • Alternative 1 – Water Conservation Program B
• Alternative 2 – Maximize Local Water Recycling
• Alternative 3 – Groundwater Remediation (Airport)
• Alternative 4 – Water Supply Exchange
• Alternative 5 – Seawater Desalination
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Alternative 1 – Water Conservation Program B
13 • Conservation Program B
• Lowest cost per unit of water
saved
• Estimated to save ~200 acre-feet
per year over the next 20 years
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Alternative 2 – Maximize Local Reuse w/SWIP
14 Project Description
This alternative will realize up to 0.9 MGD by
maximizing available capacity at:
1. SWIP AWTF product water, and
2. SMURRF effluent
The expanded reuse will include both non-potable
reuse (NPR) and direct potable reuse (DPR)
applications. The recycled water network will be
expanded to serve new NPR customers and
remaining local supply will be further treated to DPR
water quality standards at Olympic and Arcadia
treatment plants prior to potable distribution.
Sustainable Water Gain: up to 0.9 mgd
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Title 22 Advanced Treated Recycled Water Pipeline
Title 22 Diluent Water Pipeline
Blended Recycled Water and Olympic Groundwater Pipeline New Title 22 Advanced Treated Recycled Water Pipeline
SWIP AWTF
SMURRF
Groundwater
Recharge
Charnock
WTP
Arcadia
Wells
GREENSAND
FILTER
RO FEED
TANK RO DECARBONATORS
Arcadia WTP
RESERVOIR
DISTRIBUTION
Olympic AWTF
UV/H2O2 AOP GAC
Olympic
Wells
GREENSAND
FILTER
Looking to the Future:
Direct Potable Reuse
NonPotable
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Title 22 Advanced Treated Recycled Water Pipeline
Title 22 Diluent Water Pipeline
Blended Recycled Water and Olympic Groundwater Pipeline New Title 22 Advanced Treated Recycled Water Pipeline
SWIP AWTF
SMURRF
NonPotableGroundwater
Recharge
Charnock
WTP
Arcadia
Wells
GREENSAND
FILTER
RO FEED
TANK RO DECARBONATORS
Arcadia WTP
RESERVOIR
DISTRIBUTION
Olympic AWTF
UV/H2O2 AOP GAC
Olympic
Wells
GREENSAND
FILTER
FLOW
CONTROL
VALVE
PUMP
STATION
Looking to the Future:
Direct Potable Reuse
Up to 10% contribution
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Alternative 3 – Groundwater Remediation
17 Project Description
This alternative increases local supply by further
developing the Santa Monica Basin by extracting
groundwater from the Coastal Subbasin at the
Santa Monica Airport.
The groundwater would be treated by a new,
standalone groundwater treatment plant to
remove industrial pollutants.
Timing dependent on responsible party’s
characterization and remediation work.
Sustainable Water Gain: + 1.0 mgd
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Local Water Supply Alternatives
18 • Alternative 1 – Water Conservation Program B
• Alternative 2 – Maximize Local Water Recycling
• Alternative 3 – Groundwater Remediation (Airport)
• Alternative 4 – Water Supply Exchange
• 4A – Water Supply Exchange through MWD’s Pure Water So Cal • 4B – Regional IPR @ Charnock Well Field through Pure Water LA • 4C – DPR through Pure Water LA
• Alternative 5 – Seawater Desalination
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Alternative 4A – Water Supply Exchange w/MWD
19 Project Description
This alternative assumes a water supply
exchange program, where the City will purchase
water from one of two regional supply programs:
• Metropolitan's Pure Water Southern California
(PWSC) Program
• Pure Water Los Angeles (PWLA) program.
The additional water will be provided to the City
via existing Metropolitan interconnection.
Sustainable Water Gain: + 1.0 mgd
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Alternative 4B – Regional IPR at Charnock
20 Project Description
This alternative assumes diversion of purified
water from Pure Water Los Angles
(PWLA) through a new conveyance system from
the PWLA Sepulveda Alignment . This water will
be injected into the underlying aquifer using the
Charnock Well Field to maintain existing
production and potentially increase production
when needed.
New production wells will be used to extract
water and send to Arcadia WTP using the
existing Charnock Transmission line.
Sustainable Water Gain: + 3.0 mgd
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Alternative 4C – Regional DPR w/Pure Water LA
21 Project Description
This alternative assumes water from Pure
Water Los Angles (PWLA) will be diverted
through a new conveyance system from the
PWLA Sepulveda Alignment and treated using
Ozone/BAC + MF + RO at a new treatment
facility at Santa Monica Airport. The treated
water will be used for DPR via treated water
augmentation and distributed directly into the
potable water system.
Sustainable Water Gain: + 3.0 mgd
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Alternative 5 – Seawater Desalination
22 Project Description
Standalone 7 mgd seawater desalination facility
for the City as use of subsurface seawater intake
could impact local groundwater production
Emerging technologies (e.g., Oceanwell) or
partnerships opportunities (e.g. Water
Infrastructure Funding Authority) may be
available in the future.
Sustainable Water Gain: + 7.0 mgd
Photo Courtesy of Keppel
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Evaluation Criteria
23 • Environmental and Social Considerations – impacts on natural environment, public acceptance, and environmental justice • Technical Considerations - treatment process and infrastructure complexity, innovative technology, permitting, beneficial use, and maximize existing facilities
• Operational Considerations – impacts on staffing, operational complexity, and energy efficiency
• Life Cycle Cost – capital and annual operating costs
• Alignment with City’s Overall Goals – water self-sufficiency, project schedule, and control over implementation
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Preliminary Alternatives Scoring
24 Alt No.
Evenly Weighted
Emphasis on City
Goals
Alt 1 – Water Conservation Program B 1 1
Alt 2A – DPR w/SWIP + SMURRF 4 2
Alt 3 – Groundwater Remediation (Airport) 3 3
Alt 4A – Water Supply Exchange w/MWD 2 4
Alt 4B – Regional Reuse IPR 5 5
Alt 4C – Regional Reuse DPR 6 7
Alt 5 – Seawater Desalination 7 6
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Summary
25 • Near-Term Portfolio (5-10 years)
• Alternative 1 – Water Conservation
(Program B from 2024 Water Conservation Master Plan)
• Alternative 2 – Maximize Local Water Reuse with Direct Potable Reuse • Long-Term Portfolio (10+ years out)
• Regional Partnership with MWD or City of Los Angeles to increase water reuse for groundwater recharge and/or direct potable reuse • Monitor advancements in seawater desalination technology or partnership opportunities
• Monitor responsible party site clean-up
at the airport for Alternative 3
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Portfolio Implementation Approach
26 Up to 4,500 AF gap by 2045
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City Council Discussion and Input
27 • Long-Term Portfolio
• Hold formal discussions on regional partnerships with MWD or City of Los Angeles to increase water reuse for groundwater recharge and/or direct potable reuse
• Monitor advancements in seawater desalination technology or partnership opportunities
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THANK YOU…
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