Plan for offshore SFO-San Mateo sea barrier is scrapped

“As a result of that feedback, we’re now focused more on the onshore things that need to be done,” OneShoreline CEO Len Materman said. “Our project approach is to keep those things out of the Bay as much as possible. In some cases, that’s impossible, because of development that’s right close to water.” 

The new plans include raising Bayfront Park in Millbrae, incorporating either a seawall or horizontal levee on the northern stretch of the Bayfront included in the project — where existing development requires more immediate protections — and putting an onshore levee and habitat development in place on the southern stretch. 

Burlingame was an early adopter of tight zoning standards on its Bayfront that require new construction in the area to conform to a 100-year Federal Emergency Management Agency standard in exchange for upzoned parcels, which allow developers to build taller structures.

Because of this, new major projects, like Peninsula Crossing on Old Bayshore Highway just north of Broadway, will raise the shoreline and Bay Trail via private development and make it more feasible for OneShoreline to focus on other Bayfront areas most in need of sea rise defense. 

This patchworked approach will retain protection consistency and habitat redevelopment throughout, Materman said. 

“The three things that bind them all together are a consistent level of protection with sea-level rise, number two, we will improve trails where it needs improvement, [and] improve the habitat, not just on trails,” he said. 

During the Burlingame City Council meeting Dec. 1, where Materman presented the plans, Vice Mayor Michael Brownrigg raised concerns that OneShoreline was acquiescing to interest groups in letting go of its vision for an offshore barrier that could potentially provide seamless flooding protection. 

“What I fear has happened over the past two years, the boldness has been chipped away and chipped away, and we are at risk of doing the lowest common denominator solution,” he said. “We don’t have to compromise unless that compromise is the best solution.” 

When a proposal for the sea barrier came out at the end of 2023, groups like Save The Bay and Sierra Club threw into doubt the legality and feasibility of obtaining project permits for such a large-scale Bay fill and pointed to the potential environmental damage such a barrier could create. 

There was also apprehension around the proximity to SFO and the new wildlife habitat that could be created if a barrier was instituted. Typically, airports try to avoid large gatherings of bird populations due to the potential for bird strikes, which can damage airplanes in flight.

Taking a pragmatic approach to those concerns, as well as the potentially exorbitant cost of an offshore barrier, likely means taking the piece-by-piece approach, Councilmember Donna Colson said. 

“I don’t want to end up saying we’re going to build something way out in the Bay and then we have the same problem we have with the grade separation, it’s a billion-dollar project and there’s no way to fund it,” she said. “Do you want to get caught in legal and lawsuits for the next 20 years fighting the big fight, and miss the opportunity to do the smaller pieces along the way?” 

This project should have a draft environmental impact review completed by Spring 2026, Materman said, and projects across the county to protect against sea-level rise are in various stages of development. 

And San Mateo County, as one of the most sea-level rise vulnerable jurisdictions in the state, needs to be preparing now for future impact. 

“Many studies over many years made plain the fact that San Mateo County has a common vulnerability to most climate hazards, and a unique vulnerability among California counties to the issue of sea-level rise,” Materman said during the council meeting.