Chorro Flats: Chorro Creek and Floodplain Restoration

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Morro Bay is one of the most valuable estuarine resources along the south-central California coast, serving as a stop-over point and winter habitat for numerous bird species and supporting a population of steelhead trout. The Natural Resources Conservation Service (NRCS) was growing increasingly concerned about the decline in the Bay's aquatic habitat. One factor contributing to the decline was excess sediment contributions from Chorro Creek, which drains to the Bay.

ESA worked to identify causes for the Bay's decline and to develop management solutions. Using an expansive data collection program combined with a geomorphic assessment of historic maps and photos, we determined that excess sediment production from the watershed was accelerating the loss of Bay tidal waters and reducing the aquatic habitat. The team developed a plan to trap sediment on Chorro Creek, upstream of the Bay. Acquiring and restoring 100 acres of former agricultural land along the creek created dense native vegetation, which served to reduce overland flow velocities and trap excess sediment. This allowed the creek channel to reestablish its historical alignment within the floodplain. Leading a large project team, ESA prepared conceptual designs, acquired permits, garnered public support, prepared final design documents, and assisted the client with the two-phased project construction and implementation. The project performed successfully during the large floods of 1995 and 1997-1998 when it trapped several hundred thousand tons of sediment that would have previously impacted Morro Bay.

ESA identified causes and management solutions for the decline in Morro Bay's aquatic habitat. The project has received a number of awards in recognition of its benefits to the riparian habitat and contribution to the long-term health of the Bay.

Specialized Services

  • Hydrologic and hydraulic modeling