Design nearly 30% complete for restoration of Buena Vista Lagoon

Design work is nearly 30% complete, a milestone in preparations for a long-awaited restoration of the Buena Vista Lagoon at the border of Oceanside and Carlsbad, a regional planner said Thursday.

The preliminary design will include a rough time frame and cost estimate for construction that planners will review before proceeding to the next stage of the project, according to officials at the San Diego Regional Planning Agency.

“Over the last few years we’ve been doing technical investigations … and geotechnical sampling, as well as updating your vegetation map,” said Lauren Lee, a SANDAG associate regional planner, in a presentation Thursday to the Buena Vista Lagoon Joint Powers Committee.

“”We have completed 30% design and are finalizing that throughout the end of this year,” Lee said.

About $6 million is still needed to complete the design, engineering and permit work needed to get project shovel-ready, Lee said. When that is finished the agency will be able to apply for the grants needed to fund construction.

SANDAG officials said a few years ago the lagoon’s enhancement was expected to cost between $80 million and $90 million, although the amount is likely to be higher now.

The Buena Vista Lagoon is the only one in coastal San Diego County that is blocked by a weir, a low wooden dam installed in the 1970s near the beach. As a result, the lagoon is a few feet higher than sea level and filled with freshwater from rain and irrigation runoff. The fish are non-natives such as bass and carp.

Because of the weir, the 220-acre lagoon can’t flow freely to the ocean and is slowly filling with silt and reeds. The project includes the removal of the weir to restore tidal saltwater flushing to the 220-acre lagoon, along with native plants and wildlife.

During the dry summers when no water flows over the weir the lagoon becomes stagnant, sometimes filling with algae and killing off large numbers of fish. Without an excavation to remove the sediment, the open-water area will eventually be replaced by a marsh and then a meadow.

Initially the state Fish and Wildlife Department was the lead agency for the restoration. SANDAG took over in 2012 after the project reached a standstill. SANDAG’s team reached a compromise with key landowners to allow the weir’s removal, and the agency’s board approved a final environmental impact report for the project in 2020.

“Someday, hopefully in my lifetime, we will be able to celebrate the completion of this,” Carlsbad Mayor Keith Blackburn said Thursday.

As Carlsbad’s representative on the joint powers committee for about 17 years, Blackburn said that originally there were “too many cooks in the kitchen” on the project. He complimented SANDAG and his fellow long-time committee member, Oceanside Mayor Esther Sanchez, for getting the restoration on a track to success.

For several years planners hoped to to get construction funding from Caltrans as environmental mitigation for the widening of Interstate 5 that is now nearing its finish. However, the deadline for that has passed. Instead, millions of dollars from the I-5 widening was used for the restoration of the San Elijo Lagoon completed in 2022 at the border of Encinitas and Solana Beach.

Sanchez said mitigation money could become available for the Buena Vista project from other Caltrans work elsewhere in the state. Other possible sources also are being explored.