Buena Vista Lagoon weir breached; Oceanside installs temporary repairs, seeks permits for permanent fix

Jamie Timberlake, coastal zone administrator in the City of Oceanside's city manager’s office, told the Buena Vista Lagoon Joint Powers Authority that on Friday, Feb. 9, 2024, at about 10 a.m. the 50-foot weir at the mouth of Buena Vista Lagoon breached after a timber plank was dislodged likely by recent storms and high tides.

"On Friday, 02/09/2024, at approximately 10AM, City of Oceanside received notification that the 50 foot weir at the mouth of the lagoon had breached," Timberlake said, describing a rapid drop in the weir basin's elevation that compromised the structure. She said the concrete-and-timber structure was built in 1971.

City crews and contractors developed an emergency work plan and mobilized equipment to install a temporary repair ahead of forecasted large swells. "Four steel plates were placed across the gap in the weir as well as across areas where leaks were being observed and that covered approximately 20 feet of the weir," Timberlake said. She said the plates were placed and the site was demobilized and cleaned the same day; the work took roughly five hours.

Timberlake said the emergency repair was performed to prevent a rapid outflow of freshwater that could cause immediate loss of open-water habitat in the lagoon and to protect private properties from coastal flooding during elevated tides and storm surge. She said permanent repairs are still being conceptualized.

The cities of Oceanside and Carlsbad are parties to a 1971 maintenance agreement that Timberlake said assigns the two cities shared responsibility to maintain, operate and repair the weir. Timberlake said that, after the temporary emergency measures, staff will develop a conceptual design for a more permanent repair and discuss next steps with Carlsbad and the private weir owner. She added that staff expect to meet with resource and regulatory agencies and SANDAG to plan options if the weir suffers a total loss before the planned Buena Vista Lagoon enhancement project is implemented.

Timberlake listed the agencies being contacted for emergency permits: the Coastal Commission, the California Department of Fish and Wildlife, the Regional Water Quality Control Board—San Diego, and the U.S. Army Corps of Engineers. When asked whether federal or state emergency funding (for example FEMA) might be available, Timberlake said the work is maintenance and that she will look into potential funding sources and return with cost information; she said, however, that it is too early to provide a cost estimate.

Next steps described by staff include completing a conceptual design for permanent repairs, coordinating with the City of Carlsbad and the private weir owner, and meeting with regulatory agencies and SANDAG to establish options and permitting timelines. No formal action was taken at the meeting on replacement funding or a permanent repair plan.

The report and Q&A took place during the JPA's new-business item on the weir; the board did not vote on funding or design at this meeting.