Lower Redwood Creek Restoration at Muir Beach

Golden Gate National Recreation Area, CA

Golden Gate National Parks Conservancy, Muir Beach
2009

In July 2009 Hanford ARC was awarded an Indefinite Delivery/Indefinite Quantity Contract through a proposal process with the Golden Gate National Parks Conservancy (GGNPC) for creek and wetland work within the Golden Gate National Recreation Area (GGNRA).  The first task order under this contract was the first phase of a stream and tidal lagoon restoration at Muir Beach.  Redwood Creek, which flows to the ocean at Muir Beach, was restricted through historical development for ranching and recreation.  Impacts included levees, lagoon filling, and channel relocation.  The Muir Beach project, planned by the National Park Service, is a comprehensive multi-phase restoration including lagoon expansion, fill removal, channel realignment and bridge replacement.

Our scope for the 2009 work was defined by the need to provide immediate improvements for the dwindling population of Coho Salmon that rely on Redwood Creek for spawning and rearing habitat.  We substantially increased the size of the existing tidal lagoon by excavating an off-stream tidal basin, and constructed seven log structures at the perimeter of the lagoon.  The basin is fully connected to the existing lagoon, and will capture flood flows from Redwood Creek.

We restored a portion of the floodplain on the right bank of Redwood Creek upstream of the tidal lagoon.  This work involved removing approximately 40 feet from the end of the beach parking lot, including restrooms and fencing.  This was considered an interim solution, with the long-term solution being full realignment of the parking lot in a future phase.   The interim improvements to public access and the parking lot included restroom relocation, removing and resetting a boardwalk, construction of a picnic area, benches, fencing, and stabilized gravel pathways.

The project included a mitigation component as well.  California red legged frog have historically inhabited the project area.  To offset temporary impacts to the riparian habitat and to encourage potential reestablishment of red legged frog in the area, we constructed a frog pond on the east side of the historic lagoon and future channel alignment.  This work included excavation and berm construction.

Other notable components of the project included native sod salvage and replanting, screening approximately 1,000 CY of sand for weed removal, working with archeological and historically significant features, and routing public access to minimize impacts to recreational users on this very popular beach.