The City of Oceanside has begun an effort to restore the Loma Alta Slough, a coastal wetland at the mouth of Loma Alta Creek in South Oceanside. Construction started in June 2026 and is expected to continue through April 2027. The $6 million project is funded through several state and federal grant awards from the U.S. Fish and Wildlife Service, the State Coastal Conservancy, the National Fish and Wildlife Foundation, and the Ocean Protection Council.

About the Slough

The Loma Alta Slough is a rare and precious coastal estuary in South Oceanside at serves as the outlet for the 6,300-acre Loma Alta Creek watershed. Historically, the slough stretched across 44-acres of thriving coastal salt marsh. Over the past century, rapid coastal development, roadways, and infrastructure gradually reduced the wetland down to less than 10 acres. Today, the slough is an intermittently tidal estuary – where a sand berm at Buccaneer Beach opens and closes throughout the year, creating a unique shifting mix of fresh and saltwater that supportsnative wildlife.

Why Restoration is Important

Decades of urban fill, concrete channels, and invasive weeds have impacted the slough’s natural ability to function. Restoring this coastal gem delivers crucial benefits for both nature and our community:

• Restoring Endangered Habitat: the slough provides vital breeding and feeding grounds for sensitive coastal species, including the endangered tidewater goby and the rare light-footed Ridgway’s rail. 

• Improving Coastal Water Quality: wetland mud and native plant roots act as a natural filtration system, trapping urban pollutants and sediment before water reaches the surf at Buccaneer Beach.

• Strengthening Flood Defense & Climate Resilience: excavating new tidal channels allows the slough to safely absorb heavy winter stormwater.

Project Details

Since 2018, the City has obtained more than $6 million in state and federal grant funds for the project, planning, design, permitting, and construction. The comprehensive 5.8-acre habitat restoration project includes: 

• Earthwork: excavating layers of historic urban dirt fill to lower the ground elevation, allowing tidal waters to naturally flow back into the marsh.

• Habitat Restoration: removing invasive weeds and planting a diverse “habitat mosaic” of native species, ranging from coastal salt marsh and brackish marsh to upland coastal sage scrub.

• Ecotone Slopes: engineering gradual, sloped transitional zones that give the marsh space to naturally migrate uphill as sea levels rise over the next century.

• New Public Access: constructing a 1,050-foot nature trail equipped with new educational interpretative signs, connecting South Coast Highway to Buccaneer Beach and future segments of the Coastal Rail Trail. 

Looking Ahead

The City is thrilled to bring this urban wetland back to life while expanding outdoor recreational opportunities for Oceanside residents and visitors.  The construction schedule has active restoration work taking place through April 30, 2027 (Monday - Friday, 7 a.m. - 6 p.m.)

Have Questions?

For project inquiries, please contact Project Manager Bronti Cash at (760) 435-5914 or email bcash@oceansideca.org.