BVAS trail2 shapiro
BV lagoon from Maxton Brown Park
BV Lagoon S. Martin

Free The Lagoon - Supporting The Saltwater Alternative

*BV Lagoon Update - June 2020*

On May 22, 2020, the San Diego Association of Governments (SANDAG) approved a project for restoring the Buena Vista Lagoon in Oceanside, CA. This is a historic event, an almost 20-year effort in the making. Buena Vista Lagoon lies in North County San Diego, covering approximately 220 acres with most of the area owned and managed by the California Department of Fish and Wildlife (CDFW) as the state's first Ecological Reserve. Buena Vista Audubon Society manages a nature center at the edge of the lagoon's north shore.

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 2011, Buena Vista Audubon Society's Andy Mauro and Oceanside City Councilmember Esther Sanchez travelled to Sacramento and met with the Secretary of the California Natural Resources Agency, requesting that the project be restarted. Their efforts were successful; in 2012, SANDAG took the lead on lagoon restoration efforts.

SANDAG created a Draft Environmental Impact Statement (EIR) in 2015 and a Final EIR in 2018. The EIR presented three alternatives (besides no action): saltwater, freshwater, and hybrid. Last November, SANDAG was poised to vote on an alternative but delayed a decision for six months in order to work out an agreement with homeowners who threatened to sue if the saltwater alternative were selected. The homeowners, CDFW, and SANDAG ultimately agreed on a modified saltwater alternative, which keeps a portion of the lagoon (a small basin owned by the homeowners) intact as a freshwater system, with ocean saltwater bypassing this portion. The weir will be removed and the lagoon dredged and engineered to allow tidal flushing of ocean water.

Buena Vista Audubon Society supports the modified saltwater alternative and is committed to working with SANDAG as the next steps unfold.These steps include developing engineering plans, acquiring regulatory permits, creating a Master Agreement with property owners who currently hold easements to the weir, and obtaining funding for the project.

For more information on the project (environmental analysis documents) please see

The Buena Vista Audubon Society operates the nature center at the lagoon and supports the Saltwater Alternative over the Freshwater Alternative for enhancement of the Buena Vista Lagoon because of the following benefits:

  • Maximizes overall species diversity, and increases coastal saltwater wetlands, an endangered habitat;
  • Best addresses community goals of mosquito abatement, cattail reduction, reduced flooding, and beach sand replenishment;
  • Best reduces water pollution pursuant to the Clean Water Act by allowing tidal flushing and increased water circulation;
  • Best meets the objectives for lagoon enhancement as set out at the start of the EIR process; and,
  • Offers the best opportunity for enhancement project implementation through mitigation funding.

In addition, we are joined in our support for the Saltwater Alternative by the U.S. Fish & Wildlife Service, California Department of Fish & Wildlife, and California Coastal Commission.


BVAS Responds to Arguments Against the Saltwater Alternative

Click through the slides below to see how Buena Vista Audubon Society responds to Freshwater Alternative Supporters' claims. Quotation marks refer to actual statements in the Final EIR for the Buena Vista Lagoon Enhancement Plan.

Freshwater Alternative Supporters’ Claim: BVL naturally freshwater lagoon

BVAS Rebuttal

BVL “was originally influenced by both tidal and fluvial input: however, during much of the year, the lagoon was closed to the sea”(EIR chap 4). However, this condition of large expanses of dry salt flats in summer and only seasonally inundated was common to the coastal lagoons. The connections to the ocean were dynamic and intermittent. The presence of a sand berm at the mouth of the lagoon would cause closure of the inlet and could be opened by breach of the berm by either ocean waves or heavy rains sending water through the creek. The actual extent of the tidal prism is unknown, but there is historical evidence of a predominantly estuarine system of 75% salt flats and 23% salt marsh habitat at the lagoon.  Please refer to: North San Diego County Lagoon Historical Ecology study: for historical information on the coastal lagoons.

In 1940, the lagoon was converted to a freshwater system as a result of installation of a weir across the inlet that precluded saltwater from entering the lagoon. The existing weir was built in 1972, spanning a width of 50 feet. The lagoon has progressively degraded in benefits and value to biological communities, habitats and recreational uses. A 2004 study projected that between 2030 & 2050 the lagoon is expected to become a “vegetated freshwater marsh or riparian woodland-meadow”. Since 2001, numerous fed, state and local agencies and organizations have been engaged in planning for lagoon enhancement. In 2012, SANDAG reinitiated studies to design an enhancement plan for the lagoon at the request of Cities of Carlsbad and Oceanside, and it was therefore included as a component of the North Coast Corridor PWP/TREP.

Freshwater Alternative Supporters’ Claim BVL naturally freshwater lagoon BVL now supports large number of sea & freshwater birds

BVAS Rebuttal

“There are no substantial ecological values present now at the lagoon that are not represented elsewhere in the region. Our water storage reservoirs offer more freshwater habitat than ever occurred naturally. Saltwater habitats are limited to and dependent on coastal adjacency, and have experienced historical losses over time.”  “The Saltwater Alternative would have the largest benefits for biological resources, healthier benthic community, more foraging opportunities for birds and support for native salt marsh habitat & species. Threatened and endangered species would have larger nesting areas “.

Freshwater Alternative Supporters’ Claim Eco-harvesting of cattails can maintain lagoon at low cost

BVAS Rebuttal

For the Freshwater Alternative, the EIR indicates that mosquito breeding sites among the dense cattail stands would be addressed by annually creating 4-5 ft wide channels within these stands. However, this would be a costly ongoing maintenance  problem due to rapid cattail regrowth and will have annual impacts on noise, air quality, and resident wildlife. Although cattails are adapted to shallow water depths (up to 2.5 ft.) and the goal is to maintain depths at a min. 4 ft., sedimentation and organic matter buildup will reduce that depth over time in a closed system. Also, cattails when unimpeded can extend their rhizomes out into the pond surface, actually floating above much deeper waters. It is not obvious what “eco-harvesting” is and how it would be a low cost operation.

Freshwater Alternative Supporters’ Claim BVL SW Alternative would have no aesthetic water reflections

BVAS Rebuttal

The twice daily tides would fill the lagoon with seawater which would provide the aesthetic value of an open water view. These conditions would alternate with the exposure of mudflats when the tides are out, but the deeper sections would continually remain open water.  In addition, there are many examples on the California coast where houses with views of tidal lagoons are highly valued for the aesthetics.

Freshwater Alternative Supporters’ Claim SW Alternative would require condemnation of 6 acres of private property

BVAS Rebuttal

The CDFW owns and manages most of the lagoon as a State Ecological Reserve designated as the the first State reserve in 1968.  The EIR indicates that portions of the Weir Basin are privately owned by the St. Malo HOA and the weir structure & surrounding channel is owned by a private individual. Implementation of any of the alternatives would require working with land owners to obtain easements, rights-of-way, or property acquisition as necessary. SANDAG indicates that they will try to find agreeable solutions before considering the use of eminent domain. However, SANDAG has the right to “acquire, by eminent domain, any property necessary to carry out any of its powers and functions”. (Pub. Util. Code)

Freshwater Alternative Supporters’ Claim SW Alternative would create dangerous tidal ocean channel

BVAS Rebuttal

Under the SW alt, the tidal flows through the new 100 ft wide inlet are considered in the EIR to be a public health and safety impact for beach walkers and swimmers as they would not be able to safely cross when water volume and velocities are high in the channel. This is substantially mitigated by a pedestrian bridge that the EIR indicates provides “safe and convenient access” across the beach. The EIR still states that this is a significant impact not fully mitigated.  However, beach users at other lagoon and stream outlets along the coast have for a long time been cognizant of the presence of the coastal inlets, have avoided injuries from them, as they have become accustomed to use the walk arounds when necessary.

Freshwater Alternative Supporters’ Claim SW Alternative construction would take 2 yrs. with impacts - lights, noise, dust

BVAS Rebuttal

The EIR indicates that construction for both at the SW and FW alternatives is expected to take place over 15-30 months. Temporary significant and unavoidable noise, dust and air quality impacts would occur for all enhancement alternatives during construction phase, even with mitigations in place.

Freshwater Alternative Supporters’ Claim SW Alternative creates source of saltwater mosquitoes - FW Alternative with cattail removal would not be significant breeding area

BVAS Rebuttal

The Saltwater Alternative is the greatest benefit for vector control; Tides interrupt mosquito population by increased mortality of eggs, larvae & pupae; Salinity reduces ability to reproduce; Prevents stagnant breeding pools along lagoon edges; Cooler water temperatures affect larval survival; Lack of cattails better access for larvicides.(Final EIR, chap 4)

Freshwater Alternative Supporters’ Claim SW Alt would create H2S and rotten egg smell around lagoon

BVAS Rebuttal

Under existing conditions, odors can result from stagnant water, as well as intermittent fish die-off from anoxic conditions.  All alternatives would improve hydraulic conditions and reduce low oxygen events. A mild natural odor could occur for limited times when mudflats are exposed between daily tidal influx in the SW alt.  To reduce potential impacts, the SW alt was designed with narrow bands of mudflats located distances of several hundred feet between mudflats and residences or highly populated areas. Because the potential odors are short term and intermittent, only during low tide, SANDAG determined that this did not meet the criterion for a significant impact, i.e., “the creation of objectionable odors affecting a substantial number of people” and determined that the SW alt would not pose a significant impact.

Freshwater Alternative Supporters’ Claim SW Alt has a higher cost

BVAS Rebuttal

The SW alt project would be approx. 40% more costly than the FW alt due to more dredging and expansion of the Carlsbad Blvd. bridge.  However annual cattail maintenance would increase total overall project costs for the Freshwater Alternative. Most importantly, the FW alt is not sustainable over the longterm and is unlikely to function well for the expected 50 yr timeline of the project.  Sedimentation and water circulation problems would again arise and would reduce lifetime of the restoration. The result would be the need to repeat lagoon enhancement earlier than the planned project timeline which would result in a high public expense.

Freshwater Alternative Supporters’ ClaimThere has been little public outreach - no notification of meetings


SANDAG developed and executed a multi-pronged Public Participation Plan for the EIR, including meetings, written notification and also followed CEQA notice requirements.

Freshwater Alternative Supporters’ Claim SANDAG push for SW motivated by need to mitigate transportation projects and to acquire federal stimulus funds

BVAS Rebuttal

Based on the goal of meeting the project objectives set out at the start of this undertaking, and based on public and resource agency comment, SANDAG identified the SW alt as the proposed project. (EIR App P)

Conservation Through Education, Advocacy, and Monitoring

Our Mission

Conservation Through Education, Advocacy, Land Management, and Monitoring

Mailing Address

Buena Vista Audubon
PO Box 480
Oceanside, CA 92049

Nature Center

2202 S. Coast Highway
Oceanside, CA 92054



Tuesday 10 am-1 pm
Wednesday 10 am-1 pm
Thursday 10 am-1 pm
Friday 10 am-1 pm
Saturday 10 am-1 pm

Find Us

Contact Us

Please enter your name.
Please enter a message.