Resilient Wetlands

Loma Alta Slough

Loma Alta Slough is a small creek mouth estuary in the City of Oceanside. Loma Alta Creek begins as rising springs just west of Melrose Drive in the City of Vista and flows to Loma Alta Slough. Loma Alta Creek is just over seven miles long and drains nearly 6,300 acres of land. Much of the creek has been modified throughout the years, with the use of fully or partially concrete-lined channels to stabilize the creek-bed slopes. Over 70 percent of the watershed is developed with a mix of residential, industrial, commercial, and public facilities land uses.

Most of the undeveloped land contains non-native habitat, with numerous exotic/invasive plant species. The remaining native vegetation includes freshwater marsh, willow riparian scrub, coastal sage scrub, chaparral, and valley and coastal grassland. Loma Alta Creek supports approximately 100 species of wildlife including threatened and endangered species.

Over the past two hundred years, there have been significant changes to the Loma Alta Creek watershed. Loma Alta Slough used to be an approximately 44-acre lagoon, fed by an ephemeral drainage. However, over time, watershed urbanization, decreased sediment yield, hardening of the channel, degraded water quality, and wetland fill have degraded the health of the slough. Additionally, the slough itself has been filled to create developed areas, reducing the overall area available for wetland habitat. In addition to the physical loss of wetland area, water quality issues resulting from urbanization have been ongoing since the 1960s. Current dry-weather flows from the watershed provide a continuous source of fresh water that contains fertilizers and other contaminants that reduce water quality by causing eutrophic conditions and the growth of algae and bacteria. Typically, water quality problems are exacerbated when the slough is disconnected from the Pacific Ocean by the sand berm that forms naturally at Buccaneer Beach during dry periods. Intermittently opening estuaries such as the Loma Alta Slough provide unique habitats for coastally-dependent species, such as the endangered tidewater goby, but the estuary must be in healthy condition to maintain these important functions.

Loma alta heron
loma alta slough

Wetland Expansion Potential

Wetland Migration

Loma alta bird

The City of Oceanside has acquired grant funds from the State Coastal Conservancy (SCC) and the National Fish and Wildlife Foundation (NFWF) for the Loma Alta Slough Wetland Enhancement Project. The project is intended to provide benefits to the slough by improving and restoring habitat for native species, providing increased habitat resiliency to sea-level rise, improving water quality in the slough, and enhancing recreational enjoyment of the area.

The Project involves the construction of restored tidal wetlands, transitional ecotones, and upland habitat, including hydraulic improvements to existing wetlands. The project will restore the historic conditions and ecological functions of the Slough in order to increase wetland coverage, restore habitat for native species, improve recreational opportunities, and minimize public health risks.  The project area is approximately 6.8 acres, which includes 5.8 acres of City-owned property and an additional 1-acre parcel that the City plans to acquire in a future phase of the project. The Project design will consider removing fill and restoring wetlands where possible, which will allow for expansion of the existing stream channel and/or restoration of historic wetland habitats.

The wetlands restoration will remove silt and invasive plants, expand the wildlife habitat, improve water quality, and protect against flooding from sudden storm-water flows. Plans include more than 1,500 feet of nature trails with educational signs and connections to nearby facilities including Buccaneer Park. 

There are some additional parcels that could potentially be acquired and restored as wetlands. Current property owners are not willing to sell for conservation, but this may change as the properties are impacted by frequent flooding due to sea level rise.

Public Access


There is limited public access to most of Loma Alta Creek. The Loma Alta Slough is adjacent to Buccaneer Beach Park located on Pacific Street just north of Morse Street. Recreational Activities include Fishing, walking, biking, bird watching, and picnicking. Park amenities include a jungle gym, full basketball court, barbeque grills, public restrooms, picnic tables, cafe, showers, and public telephone. Approximately 40% of the City’s total population is classified as a disadvantaged community. This makes the Loma Alta Slough and Buccaneer Park an important community resource for access to nature.


The eastern end of the Loma Alta Marsh Footpath is across the street from a bus stop at Coast Highway and Salinas MHP served by the Northbound 101 and 302 buses. The Southbound stop is one block south at Coast Highway and Morse Street. The 101 and 302 buses connect to the Coaster and Sprinter at the Oceanside Transit Center. The new trail will start across the creek from the existing trailhead, making it also accessible via the 101 and 302 buses.


The Loma Alta Marsh Footpath runs along the south bank of the slough from the Coast Highway to the park and beach and provides a way to walk along the creek and watch the birds.


The Wetlands Enhancement Project includes the construction of a new public trail system north of the restored wetlands for outdoor recreation and connectivity between the beach and Coast Highway commercial corridor. The new trail will connect to Oceanside’s last segment of the Coastal Rail Trail, a separate planned city project that will include a 255-foot-long pedestrian and bicycle bridge across Loma Alta Creek with an observation deck overlooking Buccaneer Park and the nearby beach.

The Loma Alta Slough Wetlands Restoration Plan


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