Del Puerto Canyon: Haven for Wildlife, Threatened by Proposed Reservoir in the Diablo Range

Rock formations at Del Puerto Canyon

By Juan Pablo Galván Martínez


Where Is the Del Puerto Canyon Reservoir Project?

The Del Puerto Canyon Reservoir is a proposed 800-acre agricultural reservoir that would store 82,000 acre-feet of water to irrigate agriculture in the San Joaquin Valley. It would be located just west of the town of Patterson (which is 27 miles southeast of Tracy) and is being put forward by the Del Puerto Water District.

The proposed reservoir would draw water from the Delta-Mendota Canal, which is part of the federal Central Valley project that regulates and stores water in the northern half of the state. (Northern California was once considered water-rich but now often suffers drought conditions.) Then the water would be transported to the water-poor San Joaquin Valley.

Map showing proposed location for the reservoir

The proposed reservoir is located on important wildlife habitat in Del Puerto Canyon, which is part of the Diablo Range.

The Proposed Del Puerto Canyon Reservoir Would Destroy Rare Wildlife’s Habitat in the Diablo Range

The reservoir, if built, would drown a large portion of Del Puerto Canyon, a popular birding destination, and destroy more than 1,000 acres of grassland habitat and hundreds of acres of oak woodland, riparian, and other wetland habitat.

San Joaquin kit fox, American badger, golden eagle, burrowing owl, California red-legged frog, foothill yellow-legged frog, and California tiger salamander would be affected by this project. These are just some of the rare wildlife species that would be disrupted.

San Joaquin kit fox with kits in grass

Del Puerto Canyon has habitat for the endangered San Joaquin kit fox and many other vulnerable species. Photo by Scott Hein.

Reservoir Approved, Lawsuit Filed to Challenge It

The reservoir has been approved by the Del Puerto Water District. Save Mount Diablo has supported a lawsuit that challenges the project’s approval.

The lawsuit has been filed by the Sierra Club, Center for Biological Diversity, California Native Plant Society, and Friends of the River based on the inadequacies of the project’s environmental review. We are also awaiting the release of the project’s federal environmental impact statement, expected sometime in the next few months, and will review and comment on it.

Landscape at Del Puerto Canyon

Del Puerto Canyon provides many different types of habitat for wildlife. Photo by Al Johnson.

We continue to work with partners to challenge this project and increase the protection of wildlife and habitat in this part of the Diablo Range.

Top photo by Sean Burke.

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