San Francisco prides itself on providing some of the best municipal drinking water in the country. But by relying on Tuolumne River water piped in from Yosemite National Park, The City lacks some of the local water resources — like groundwater and recycled water — enjoyed by larger California cities like Los Angeles.
The biggest potential local supply is undrinkable — the salt water in the Bay. The Bay Area’s biggest water agencies have been studying since 2002 where and how to build a desalination plant.
If approved, the most likely location for the Bay Area Regional Desalination Project, which would convert 20 million gallons of salt water to fresh water a day, is Contra Costa County.
Those plans, as well as efforts to build a water recycling plant on The City’s east side, may be on hold for now, San Francisco Public Utilities Commission Assistant General Manager Steven Ritchie said Tuesday.
An extra $161 million in costs required to finish the so-called Water Systems Improvement Project and to start gleaning drinking water from groundwater will be paid out of money set aside for the desalination plant, Ritchie said. The WSIP — a seismic rebuild of the dams, tunnels and pipes that deliver SFPUC water to 2.6 million Bay Area homes and businesses — exceeded its $4.6 billion budget thanks to construction overruns like the one at Calaveras Dam, where the discovery of ancient landslides made the job more difficult.
The SFPUC delivers 265 million gallons of water a day. That demand is expected to exceed 285 million gallons a day by 2018, according to the commission.
The SFPUC is exploring ways to provide 20 million gallons a day from local sources over the next decade, and recycled water, as well as conservation and desalination, is “a big chunk of how we get there,” SFPUC Commissioner Anson Moran said Tuesday.
The proposed desalination plant “or something else needs to be very high on our priority list,” he said.
Recycled water is also considered vital to The City’s future development plans: a recycled water plant on The City’s east side would help provide the water that new developments on the east side would use to flush toilets. Plans to retrieve some water from the ground will still go forward, as the first groundwater wells are scheduled to be dug later this year.
Funded or not, any potential groundbreaking of the desalination plant is still years in the future.
The SFPUC could choose to re-fund the desalination plant in two years as part of its next budget cycle, Ritchie said.