Stanislaus County approves new road to bypass proposed reservoir. Court decision reversed
Stanislaus County supervisors approved a new route Tuesday for Del Puerto Canyon Road to make way for a reservoir west of Patterson.
The proposed reservoir, just west of Interstate 5, would inundate a section of the road that winds through Del Puerto Canyon. Supervisors approved a 3.9-mile alternative route starting at Del Puerto Canyon Road, about half a mile from the intersection of Sperry Road and Interstate 5. From there, the new road will cross over foothill terrain to reconnect with Del Puerto Canyon Road near the 5-mile mark in the canyon.
According to a study that analyzed 10 possible routes, the new road will traverse through a valley for 1.25 miles and cross a bridge before reaching the canyon near the mouth of the reservoir. A preliminary estimate for the road’s cost is $110 million, which is the responsibility of the reservoir project.
County Public Works Director David Leamon said there’s an opportunity for a scenic overlook on the route. Another official said most residences in the cattle grazing area are west of the 9-mile mark. The new road will give canyon residents a route around the storage reservoir and also provide public access to Frank Raines Park and the adjacent off-road vehicle area.
The study found that 95% of vehicle trips on Del Puerto Canyon Road use Interstate 5.
Del Puerto Water District and the San Joaquin River Exchange Contractors Water Authority are proponents of the reservoir, which would store up to 82,000 acre-feet of water pumped south of the San Joaquin-Sacramento river delta. Proponents say the reservoir will store water in wet years and release it in dry years to West Side farmers, who may struggle with zero drought-year allocations from the Central Valley Project.
Water would be pumped into the reservoir from the Delta-Mendota Canal.
The Sierra Club and other environmental groups filed a lawsuit in November 2020 challenging the environmental impact study for the $1.8 billion reservoir project.
Stanislaus Superior Court Judge John Mayne ruled in October 2022 that the environmental study failed to address the relocation of Del Puerto Canyon Road and ordered Del Puerto Water District to decertify the EIR.
The state’s 5th Appellate Court disagreed in a ruling last week but said the study was insufficient in ignoring impacts on species on land along Del Puerto Creek, downstream from the proposed the dam. The ruling will require some additional work on the EIR.
Anthea Hansen, general manager of Del Puerto Water District, said experts have concluded two years of geotechnical studies for the dam. “We continue to hear it’s an ideal spot for an off-stream storage reservoir,” Hansen said. “We continue to move the project forward.”
According to the proposal, payments from agricultural water users, as well as state and federal funding, would pay for the new reservoir.
