SAN JOSE—On Monday, Aug. 14, the Santa Clara Valley Water District submitted an application to the California Water Commission requesting $484.5 million, half of the capital cost of a project to expand Pacheco Reservoir near the southeastern border of Santa Clara County.
The funding would come from the $2.7 billion Water Storage Investment Program, part of California’s Water Quality, Supply, and Infrastructure Improvement Act of 2014, a $7.5 billion bond passed by California voters.
The project would establish a new dam and expanded reservoir on the North Fork of Pacheco Creek that could hold 141,000 acre-feet of water, an increase from the 6,000-acre-foot capacity of the existing reservoir. Constructed in 1939 and used for groundwater recharge, the reservoir is located about 13 miles southwest of San Luis Reservoir, off Highway 152.
The project’s potential benefits are vast, including benefits to the environment, emergency response, water supply, water quality and flood control, including the following:
Increase suitable habitat in Pacheco Creek for the federally threatened South Central California Coast steelhead.
Develop water supplies for environmental water needs of wildlife refuges to support habitat management in the Delta watershed.
Reduce flood risks for disadvantaged communities along Pacheco Creek and Pajaro River as it flows through Watsonville
- Improve water quality, reducing taste and odor problems that result from seasonal algae blooms in San Luis Reservoir and cause Santa Clara Valley Water District operators to curtail deliveries from this source.
- Provide an emergency water supply to Santa Clara and San Benito counties.
- Increase reliability of imported water supplies to Santa Clara and San Benito counties.\
- Provide additional water for groundwater recharge, benefitting agricultural water users downstream of the new dam.
- Increase operational flexibility of water supplies at San Luis Reservoir and throughout Santa Clara County.
- Improve opportunities for water transfers through San Luis Reservoir.
District Board Member Gary Kremen, who chairs the water district’s Pacheco Reservoir Exploratory Ad Hoc Committee, said, “It is not often that we encounter an opportunity to build something that will have such profound benefits for the environment, flood control and water supply. There are few suitable spots in California for new water storage, and fewer still that substantially help threatened fish species. We’re fortunate to have one of those spots in our backyard.”
The expanded reservoir would be filled with storm runoff from the surrounding watershed, and would also be used to store water imported through the Sacramento-San Joaquin Delta. The project would include a new earthen dam and spillway. It includes new pipelines, tunnels and a pump station to connect the new reservoir to the Pacheco Conduit, which is an existing pipeline near Highway 152 that conveys water from San Luis Reservoir to Santa Clara and San Benito counties.
Key project partners include the Pacheco Pass Water District, San Benito County Water District and eight wildlife refuges in the San Joaquin River Hydrologic Region. Support letters from 46 California state legislators, organizations, resource conservation districts, water agencies and individuals were included in the application.
The estimated benefits of the project far outweigh the costs, leading the project partners to feel optimistic about receiving substantial state funding.
Jerry J. Smith, Ph.D., a fisheries biologist with experience studying Pacheco Creek since 1972 wrote, “The additional storage in the enlarged reservoir would potentially allow for increased releases from the reservoir into Pacheco Creek for rearing, including expanding releases to drought years when the existing reservoir would have insufficient storage to provide adequate releases for rearing steelhead. In addition, the deeper reservoir (with an expanded depth of cool bottom water) would provide for cooler releases throughout the summer-fall juvenile steelhead rearing period.
Josué García, chief executive officer of the Santa Clara & San Benito Counties Building and Construction Trades Council wrote, “This investment in our future will create both short and long term jobs as well as increase local control of the water supply. Together, these changes will create consistent economic growth for the entire Silicon Valley.”
Jason Peltier, executive director of the San Luis and Delta-Mendota Water Authority wrote, “The Pacheco Reservoir Expansion Project can provide a multitude of benefits, not just to California’s agriculture and the communities we serve, but also broad public benefits including protection against flood, groundwater overdraft and subsidence, and more water for environmental management.”
Sharon K. Tapia, chief of the California’s Division of Safety of Dams wrote, “From a dam safety perspective, we are pleased that SCVWD with its expertise and resources are pursuing this Enlargement Project, which will also incorporate the resolution of the long-standing spillway deficiencies at North Fork Dam. As a responsible dam owner, SCVWD continues to demonstrate a strong commitment to dam safety and to work cooperatively with DSOD on its major rehabilitation projects that are currently underway.”
Last week, the district posted an Initial Study and Notice of Preparation for the project at http://www.valleywater.org/PublicReviewDocuments.aspx. Comments to the NOP can be submitted by Sept. 11, 2017.
The Executive Summary of the water district’s Prop. 1 application is posted at http://www.valleywater.org/PachecoReservoirExecSummary. The entire application package is available at https://fta.valleywater.org/fl/FrmL4f0ukW.