Park District Celebrates Grand Opening of Alder Creek, Leatherwood Creek Restoration

The East Bay Regional Park District Board of Directors and staff celebrated the grand opening of the Alder Creek and Leatherwood Creek Restoration Project at Sibley Volcanic Regional Preserve on May 23. This is the largest creek restoration project in the Park District’s 90-year history. This project restores 3,000 linear feet (approximately half a mile) of previously culverted creek to more natural conditions and is now open to the public.

The Alder Creek and Leatherwood Creek Restoration Project, formerly known as the McCosker Project in honor of the last family who owned and worked on the property, provides natural habitat for special status or protected species, including the California red-legged frog, California foothill yellow-legged frog, Alameda whipsnake, San Francisco dusky-footed wood rat, golden eagle, Cooper’s hawk, loggerhead shrike, northern harrier, and white-tailed kite. The project's water quality and streamflow improvements now also provide new habitat for rainbow trout, a native salmonid species. 

“This is an area of Sibley Volcanic Regional Preserve has undergone great transformation,” said East Bay Regional Park District Board President Elizabeth Echols. “The project is the largest creek daylighting project in the entire Bay Area, with new access to the beautiful and important Alder and Leatherwood creeks in the upper San Leandro Creek watershed.” 

The 250-acre site is situated within a deep canyon of dense oak woodland at the bottom of a ridgeline of rolling grassland hills. When the Park District acquired the property in 2010, the creeks within the property had been buried underground in culverts to make room for the rock quarrying operations that historically took place there. When the Park District took ownership of the property, the culverts were deteriorating, creating hazardous conditions and jeopardizing the surrounding recreation areas.

“You may not realize it by looking at it today, but this land was once graded flat and used as a homestead, ranch, farm, paving and quarry operation, and equipment yard,” said Park District Board Member Dee Rosario whose Ward includes Sibley Volcanic Regional Preserve. “The project restored 3,000 feet of previously culverted creek back to a more natural condition to function as riparian habitat. A great feat for the Park District and a success story for all environmentalists fighting to protect the environment and restore habitat.”

The project was made possible through funding secured by Assemblymember Rebecca Bauer-Kahan in the 2019 state budget. Additional funding came from the Park District’s voter-approved Measure WW and other state and federal grants from the U.S. Environmental Protection Agency, Wildlife Conservation Board, Coastal Conservancy, California State Parks, and voter-approved Propositions 1, 84, and 50 allocated by the California Natural Resources Agency. 

“We thank Assemblymember Rebecca Bauer-Kahan for her leadership in Sacramento and all our funding partners that helped make this happen,” said East Bay Regional Park District General Manager Sabrina Landreth. “We especially thank all District staff who worked on the project for over 10 years.” 

The restoration project also addresses climate change by increasing flood capacity on the site, removing invasive species, increasing the carbon sink, enhancing habitat, and adding vegetation. In support of inclusive public access, additional enhancement work includes new nature trails and future amenity areas. The restoration effort has significantly enhanced creek and riparian functions and provides numerous benefits to native and special status species in alignment with the state’s 30x30 biodiversity and climate resiliency goals.   

The restoration area within Sibley Volcanic Regional Preserve is open to the public. It includes an 11-car staging area off of Pinehurst Road, with connections to the McCosker Loop Trail and trails that follow the creeks on the property. Temporary restroom facilities are available while Phase 2 of the project is underway. Phase 2 of the project includes establishing a group campsite and permanent restroom facilities. 

Visit https://www.ebparks.org/projects/sibley-alder-and-leatherwood-creek-restoration-and-public-access-project-mccosker-project for more information.