Starting as a trickle on the eastern slopes of Mt Diablo, Marsh Creek meanders through Brentwood and Oakley and empties into the San Joaquin River at Big Break. Along the way, Dry Creek, Sand Creek, Deer Creek, Curry Creek and Round Valley Creek serve as tributaries. The Marsh Creek Watershed covers approximately 75,000 acres. Although heavily impacted by development the creek still supports a fall run of Chinook salmon. A significant impact on this annual migration is a concrete structure that prevents salmon and steelhead trout from reaching spawning habitat in the upper reaches of Marsh Creek.
In a recent report it was found that upstream from the concrete barrier there is suitable gravel quality, quantity, and vegetative cover to support Chinook salmon spawning. In addition, potential spawning and over-summering habitat for both steelhead and Chinook is available.
Contra Costa County Flood Control and Water Conservation District (Flood Control District) and its partners have started construction of a Fish Ladder on Marsh Creek to bypass the concrete barrier. This project is a partnership with American Rivers, the Natural Heritage Institute, the Flood Control District, Contra Costa County, the City of Brentwood, the California Department of Water Resources, National Oceanic and Atmospheric Administration, the California State Coastal Conservancy, the State Water Resources Control Board, the Natural Resources Conservation District, the East Bay Regional Parks District, and the Friends of Marsh Creek Watershed.
The fish ladder will enable salmon and steelhead fish to migrate past the concrete structure to spawning habitat in the upper reaches of Marsh Creek. The work consists of installing a series of small stepped resting pools along the north side of the existing structure to allow the fish to travel around the six-foot-high wall of the structure. The work is scheduled to be completed by the end of October.
To view the site, take the Marsh Creek trail between Delta Road and Brentwood Boulevard and head south. The trail will be open during construction. The project is also being tracked online at the Friends of Marsh Creek Watershed website.