October 2021 saw the completion of the initial restoration phase of the more than 10-year effort to restore floodplain and habitat on the Los Osos Creek Wetland.  Several state, local and federal partners funded the initial acquisition of the property, the development of a restoration plan, engineered design plans and the environmental review process—and finally implementation.  

Initial restoration phase activities included reconnecting the historic floodplain connectivity by breaching 400 feet of levee and replacing three perched culverts with fish-passage-friendl low-water crossing. Construction took place during four weeks and was completed days before the first rains of the season. During late winter storms in 2021 and 2022, floodwaters of Los Osos Creek reconnected with their historic floodplain for the first time in nearly 100 years, reinitiating the natural hydrology of the floodplain. During construction activities, RCD staff saw more than 60 California red-legged frogs, a pair of Cooper’s hawks, a family of black-tailed deer and evidence of a mountain lion.

Restoration activities continued in 2022 with native riparian and upland plantings led by the California Conservation Corps, including an outplanting of the Federally Endangered Marsh sandwort and Morro Manzanita, and removal of invasive cape ivy and iceplant. 2023 will see the the final phase of restoration, for now, including the relocation of PG&E utility infrastructure outside of the wetland, decommissioning of an access road, and continued invasive species management. 

As a result of this restoration project, 50 acres of wetland and 16 acres of coastal dune scrub habitat will be restored, and a key barrier to fish passage will be removed, enhancing habitat for Steelhead, Tidewater goby, California redlegged frog, Least Bell’s vireo, Marsh sandwort and Morro manzanita.

Partners: MBNEP, NRCS, MCAS, CLC, SLO County, USFWS, SCC, WCB, CCC, Morro Dunes State Park

Funders: USFWS NWCW, SCC, WCB

RCD Contact: Hallie Richard, hrichard@coastalrcd.org

View this video for the story of the Los Osos Wetland Restoration project.