Resilient Wetlands

Buena Vista Lagoon

Buena Vista Lagoon is located in northern San Diego County, within the cities of Oceanside and Carlsbad. The Buena Vista Creek Watershed extends approximately 10.60 miles inland from the coast and totals 14,437 acres in area. Buena Vista Creek originates on the western slopes of the San Marcos Mountains and discharges into the Pacific Ocean via Buena Vista Lagoon. 

The lagoon covers 223 acres of wetland habitat and serves as a geographic border between Carlsbad and Oceanside. Buena Vista Lagoon is managed by the California Department of Fish and Wildlife. The lagoon is home to the Buena Vista Audubon Society Nature Center and is California’s first Ecological Reserve. Two non-profit organizations are committed to the preservation and management of the lagoon: the Buena Vista Audubon Society and the Buena Vista Lagoon Foundation.

Buena Vista Lagoon was acquired to preserve, protect, and maintain coastal wetland habitat and associated wildlife species. The property was designated as an ecological reserve by the Fish and Game Commission in 1968.

Buena Vista Lagoon is the only freshwater lagoon in Southern California, protected from tidal influence by a beach berm and a man-made barrier, known as a weir, located at the lagoon mouth. The Buena Vista Lagoon Ecological Reserve is 206 acres of coastal freshwater lagoon habitat. Flora includes widgeon grass, pondweed, and arrow grass. Birds include cormorants, grebes, passerine birds, terns, ducks, and geese. Mammals include raccoon, skunk, and opossum, as well as vole and western harvest mouse. The lagoon harbors at least 103 bird species, 18 mammals, and 14 amphibians and reptiles. Buena Vista also serves as a valuable wetland habitat for migrating bird species during the fall months.

Buena Vista Marsh view
bird buena vista
Buena vista path

Restoration Efforts

Buena Vista Lagoon has been slowly filling up with reeds and sediment since it was dammed in the early 1970s by a weir at the mouth. Historically, the lagoon was both a saltwater and freshwater environment, depending on the influence and timing of ocean tides and upland streamflow. If nothing is done, the lagoon will eventually become a wet meadow and North County will lose an important piece of habitat for resident and migratory birds.

In 2004, CDFW led efforts to restore the lagoon; however, stakeholders failed to agree and the efforts stalled. Property owners near the lagoon’s mouth hold easement rights to the weir and also own a small portion of the lagoon. Fearing that removing the weir would drain the Lagoon and replace it with mud flats, they insisted that it remain a freshwater system, with the weir kept in place. Conservation groups, including the Buena Vista Audubon Society, advocated for the weir’s removal in order to become a saltwater environment. Removing the weir would allow the lagoon to connect to the ocean and to maintain a variety of saltwater habitats, subject to tidal influences. Currently, there are no mud flats along the lagoon’s edges. Mud flats are being lost elsewhere due to sea-level rise and thus a saltwater lagoon would provide this critical habitat for shorebirds. A saltwater lagoon would also function as a nursery for ocean fish, improve water quality,  reduce severe infestations of mosquitoes, and reduce flooding.

In July 2022, State Fish and Wildlife Department officials awarded a $1 million grant to the San Diego Association of Governments for planning the restoration of the Buena Vista Lagoon at the Oceanside-Carlsbad border. The $1 million adds to $3 million the state Wildlife Conservation Board awarded in 2021 to SANDAG for the proposed cleanup of the stagnant 220-acre lagoon. The new grant gives the agency about half the money it needs to finish the engineering and design work that must be completed before the project can be offered for construction bids.

No funding has been allocated so far for construction, which is expected to cost between $80 million and $90 million. The restoration should be finished in three to four years after the construction contract is signed. Much of the lagoon will be excavated to remove the silt and cattails that have been slowly filling the basin for decades and to open a new channel to the ocean. The weir at the outlet will be removed to allow ocean water to flow in and out, changing what has become a freshwater marsh back to a saltwater wetland.

Wetland Expansion Potential

Wetland Migration

The lagoon has already expanded due to the 8-foot weir at the mouth, which raised the water level to about where it will be with 8 feet of sea level rise. The immediate result of the restoration project will be to drop the water level to current sea level. This will shrink the open water area, while expanding the tidally influenced marsh area, for a type change and net gain of salt marsh function. The short-term gain will eventually be lost again as sea level converts it back to open water.

There is only a small area in the northeast corner that allows some actual expansion. Several small parcels owned by Caltrans could be added to the reserve.


Wetland expansion is constrained by a combination of topography, development, and infrastructure.

Public Access


The Buena Vista Lagoon is the home of the Buena Vista Audubon Society which operates a small but very informative Nature Center on the north edge of the lagoon. Two trails near the Nature Center offer many opportunities to see the lagoon inhabitants. Picnic facilities are also available.

There is a short loop trail at the Buena Vista Audubon Nature Center.


The Audubon Nature Center and trailhead is a short walk from a northbound 101 bus stop at Coast Highway and Eaton St, and about 1/3 mile from a southbound 101 bus stop and a 302 bus stop at Coast Highway and Vista Way. The 101 bus connects to the Coaster and Sprinter at the Oceanside Transit Center, and to the Coaster at the Carlsbad Village station. The 302 bus connects to the Coaster and Sprinter at the Oceanside Transit Center and to the Sprinter at the Vista Transit Center.

More Resources:

Buena Vista sign


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