Early insight on San Francisco’s highly ambitious £10.5bn sea rise protection project

Released in January, the Port of San Francisco’s San Francisco Waterfront Flood Study - Draft Plan looks at the options available to defend the city’s 12km shoreline from roughly 1-2m sea level rise expected by 2100. It is the first of its kind from the US Army Corps of Engineers (USACE).

The plan was put together in a collaboration by the Port of San Francisco, the USACE, Jacobs and Arcadis. It is based on analysis of the coastal flood risk and effects of sea level rise for the waterfront within the Port of San Francisco’s jurisdiction, from Aquatic Park to Heron’s Head Park.

It also includes capacity to also build resilience against seismic events that are frequent in the Bay Area of California.

Jacobs programme manager for the project Darren Milsom told NCE that, while the project will completely change the way San Francisco is built, doing nothing will inevitably lead to irreparable damage to the communities that inhabit the city.

“There has to be an acknowledgement that doing nothing would have a much greater impact than doing something,” he said. “So how do we do it in a way that minimises impact?

“Not only just that but it’s also important to see it as an opportunity to reimagine what the San Francisco waterfront, this kind of world renowned waterfront, can look like in in 40 years, and how we can make it even better than it is now.”

The Embarcadero waterfront contains historic piers, wharves and buildings, including the historic Ferry Building. Milsom pointed out that residents consider these landmarks central to the thriving Port.

This section of the waterfront also contains the Embarcadero Promenade that hosts millions of people annually from all over the world and provides flood protection to San Francisco’s Financial District.

To combat the potential impacts of sea level rise due to climate change, the Draft Plan focuses on raising the seawall at the shoreline edge. This would be done in a gradual transition to connect the shoreline to the existing city elevation across the Embarcadero, maintaining the city’s connection to the waterfront while also adapting historic wharves and buildings.

Maintaining the city’s iconic appearance is key, according to Milsom.

“We have these bulkhead buildings, where a number of San Francisco’s iconic ferry buildings are all based over the water,” he said “They’re all on piles connected to the shoreline and connected to the 100-year-old sea wall.

“San Francisco is the City By The Bay so we made it very clear we didn’t just want to build a wall along the edge and prevent it being the City By The Bay anymore. That would cut everybody off from the water.

“We wanted to be able to elevate the shoreline and maintain some connectivity to the Bay so that’s the plan that’s been developed.

“We will gently try and grade it back down and you should end up with, hopefully, a world class urban environment.”

Perhaps the most ambitious part of the plan “includes raising all of the bulkhead buildings and the ferry buildings that are currently sitting over the water to match the new grade”, according to Milsom.

“It’s a significant undertaking to do that, these buildings are over 100 years old, many of them, and they're very large,” he said. “Having to lift them up is a huge undertaking, it will take a lot of time.”

The Port of San Francisco’s plan for the waterfront was developed alongside crucial insight from San Francisco bay locals.

The plan doesn’t just focus on the Embarcadero area of San Francisco.

In Fisherman’s Wharf, the study looks at taking advantage of the existing higher ground and will look to use floodproofing and short floodwalls on piers and wharves to reduce near-term damages to lower-lying buildings and assets.

In South Beach, Mission Bay, Islais Creek and the Bayview area, a combination of berms/levees, seawalls, nature-based features such as creek enhancements and closure structures for light rail bridges is proposed.

Another landmark element of the study is it is the first time the USACE has based its findings on regional economic impacts to the county and the city, whereas before the reports had looked at impacts to the whole of the US.

“The overriding response to the plan is positive and I think in part that's because we've been able to take this different approach,” Milsom said.

“Would you have come up with something different, less beneficial and something that might not have gained as much public support had it been purely based on federal economic justification?”

While this study regional approach is a first for the USACE - which Milsom remarks is due to “fortuitous timing” - it is also something the organisation plans to roll out for future studies.

Consultation on the study ended at the end of March this year.

The next major milestone for the project will come in March 2026 when a proposal to Congress will recommend for it to make federal investment in the project. Current plans would see Congress pay for 65% of the construction costs, which could amount to up to $8bn (£6.5bn).

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