Santa Monica resets water self-sufficiency outlook at 80-85%

Santa Monica resets water self-sufficiency outlook at 80-85%Santa Monica’s Sustainable Water Master Plan update finds that completed infrastructure projects have materially expanded local supply, but pandemic delays, groundwater constraints and peak demand leave the city short of its former 99% self-sufficiency target. The recommended near-term portfolio combines expanded conservation with direct potable reuse.

Staff estimates existing local supplies can meet about 80-85% of Santa Monica’s annual water demand, subject to confirmation once two replacement Charnock Well Field wells enter service.

The recommended near-term portfolio is expanded conservation plus recycled-water distribution and direct potable reuse; both are already included in the city’s adopted 2025 water and wastewater rate study.

The 2024 Water Conservation Master Plan’s strategic programme projects annual savings of 924 acre-feet by 2045, or 9.1% of baseline demand, at an average utility cost of $730 per acre-foot saved.

Longer-term options include groundwater remediation beneath Santa Monica Airport, regional water-reuse partnerships with Metropolitan Water District and LADWP, and monitoring of emerging seawater desalination technologies.

Santa Monica has revised its water self-sufficiency expectations downward, with city staff estimating that local sources can currently meet around 80-85% of annual demand rather than the 99% target set under its 2018 Sustainable Water Master Plan. The revised position was presented to City Council on 22 September as part of a Sustainable Water Master Plan update. Staff said the city’s actual local production capacity will not be fully known until two replacement groundwater wells at the Charnock Well Field are completed and operational, which is anticipated by the end of 2026. Santa Monica adopted its water self-sufficiency strategy in 2018 to diversify supplies and reduce imported-water dependence. The programme was intended to combine conservation, alternative supplies and expanded groundwater production. Most projects were completed by January 2026, but conservation expansion, recycled-water network extensions and new groundwater production were delayed by the Covid-19 pandemic, staffing reductions, financial constraints, supply-chain disruption and regulatory delays. Completed projects include the Sustainable Water Infrastructure Project, which treats stormwater, urban runoff, municipal wastewater and brackish groundwater for aquifer recharge and non-potable uses. The city also completed the Olympic Well Field restoration programme, including two new production wells and an advanced treatment facility for industrial contaminants, and upgraded the Arcadia Water Treatment Plant with flow-reversal reverse osmosis technology. The upgrade is intended to increase plant efficiency to 90% or more and produce about 10% more potable water without additional groundwater pumping. The update identifies conservation and expanded local recycling as the near-term portfolio for the next five to 10 years. Staff proposes implementation of the strategic programme in the city’s 2024 Water Conservation Master Plan, alongside expansion of recycled-water distribution and direct potable reuse. The latter would add the city’s advanced-treated recycled water to its drinking-water supply after further treatment. The strategic conservation programme includes 13 measures, including advanced-metering-infrastructure leak alerts, fixture rebates, landscape conversion incentives, irrigation-device installations, residential and commercial water audits, direct-install programmes and dedicated-irrigation-meter compliance. It projects 924 acre-feet of annual water savings by 2045, equal to 9.1% of baseline demand. The plan estimates an average utility cost of $730 per acre-foot saved between 2023 and 2045, compared with approximately $1,250 per acre-foot for Metropolitan Water District imported supplies in 2024. Staff said two additional full-time positions would be needed to implement the strategic conservation programme and respond to new state conservation requirements. For the longer term, the update retains several supply options for further assessment: remediation of contaminated groundwater in the Coastal Sub-basin beneath Santa Monica Airport; regional water supply exchanges and reuse partnerships with Metropolitan Water District and the Los Angeles Department of Water and Power; and possible seawater desalination. Staff noted that regional projects are not expected to operate until after 2035, while desalination remains significantly more expensive than the other alternatives evaluated.