Critics of plans to build a huge new reservoir in Santa Clara County near Pacheco Pass have filed a lawsuit against the proposed $2.5 billion project, presenting a new hurdle for what would be the largest reservoir constructed in the Bay Area in more than 20 years.
The group, called the Stop the Pacheco Dam Coalition and made up of environmentalists and landowners whose rural ranchland property would be flooded, sued the Santa Clara Valley Water District in Santa Clara County Superior Court earlier this month.
In the suit, opponents allege that the water district, a government agency based in San Jose, violated state law when it decided not to conduct environmental studies to measure how upcoming drilling, boring and other geological tests will affect sensitive plants, wildlife and archaeological sites on the rugged landscape where the dam is planned just south of Henry W. Coe State Park.
“It’s a very wild place. The North Fork of Pacheco Creek is full of rare plant life and wildlife. It is pristine. It is habitat for endangered species. I have seen eagles down there,” said Osha Meserve, a Sacramento attorney representing the dam opponents.
On Tuesday, the water district, also known as Valley Water, issued a statement saying it has not violated the law.
“Valley Water has complied with all environmental requirements for this work and will continue to do so for the length of this project,” said Matt Keller, a district spokesman.
The geological work in question would require contractors to spend eight to 17 months drilling 226 borings and digging 57 test pits, up to 20 feet deep on various properties, including several private ranches that would be flooded by the dam. Trucks, trailers, heavy equipment and helicopters would need to make hundreds of trips over the landscape, the lawsuit notes.
The lawsuit says that the water district violated CEQA — the California Environmental Quality Act — a law signed by former Gov. Ronald Reagan in 1970 that requires detailed studies of major construction projects. It is asking a judge to order the district to do the studies and add them to a draft environmental impact report the district released last November.
The additional studies could potentially take a year or more.
The district’s plan calls for building a 320-foot-high earthen dam on the North Fork of Pacheco Creek in the rugged canyons about 2 miles north of Highway 152.
Construction would start in 2025 and finish in 2032. The reservoir would submerge 1,367 acres and have a 35-mile shoreline.
The new reservoir would hold 141,000 acre feet of water, replacing a small reservoir there now that was built in 1939. The new Pacheco reservoir — 23 times bigger — would be built upstream.
It would be the largest new reservoir built in the Bay Area since 1998 when the Contra Costa Water District constructed the Los Vaqueros Reservoir in eastern Contra Costa County. It would also rank as the fourth largest reservoir in the Bay Area, behind Lake Berryessa in Napa County, Lake Sonoma in Sonoma County and Los Vaqueros.
The district hopes to take water it now stores nearby in the massive San Luis Reservoir and pipe it to a new Pacheco reservoir, filling it during wet years.
“We entered this winter in a drought emergency,” said John Varela, the district’s acting chairman, at a public hearing on the project Jan. 13. “Increasing our ability to store water in wet winters to use during droughts is vital to the region , especially in light of the fact that climate change is already resulting in more frequent, more severe droughts.”
District officials say that the project would also provide a more regular supply of water downstream for endangered steelhead trout.
The project received a huge boost in 2018 when the administration of former Gov. Jerry Brown awarded it $485 million from Proposition 1, a $7.5 billion water bond passed by voters in 2014. The district met a key deadline for the state funding when it released its draft environmental impact report for the project in November.
But it has run into big problems with cost overruns. In 2017, the district estimated the project would cost about $800 million. The following year, the price jumped to $969 million, then $1.3 billion by 2020. In January 2021, the district announced the cost had doubled again to $2.5 billion after initial geological studies found rock in the area was unstable — a finding that geologists had noted 20 years earlier when the water district considered, and then dropped, the idea.
In recent months, the price dipped to $2.3 billion after design revisions, but currently is back to $2.5 billion, district officials said Tuesday.
Critics, who include San Jose Mayor Sam Liccardo, say the price tag is far too high. They note that the district’s staff in April 2021 issued a report showing the cost would be $18,800 an acre foot, double the cost of expanding Los Cowboys in Contra Costa County or raising the height of Sisk Dam on San Luis Reservoir. It’s also 20 times the cost of groundwater storage projects in the San Joaquin Valley and Palm Desert areas that the district could use.
The district also has not secured any federal funding or funding from other Bay Area water districts to help pay the bill, meaning its ratepayers could be on the hook for all costs.
Meserve said the district should focus instead on expanding recycled water, on stormwater capture projects and more groundwater storage.
“There are 1,500 reservoir sites in the state,” she said. “If you are ranking them this is probably the 1501st. Most of the good sites are taken. This isn’t one of them.”