As the executive director of the Port of San Francisco, you might assume Elaine Forbes dreads the annual appearance of naturally occurring king tides, which flooded portions of the Embarcadero back in mid-December.
But Forbes said she actually looks forward to the biannual tides, which are set to return to San Francisco tomorrow.
“I get excited when people think about them,” Forbes said. “They really show us what our future with sea level rise is going to look like.”
According to the National Research Council, that future could be perilous for San Francisco's coastline. Given the current rate of sea level rise, average tides in San Francisco are set to rise by between three and five feet by 2100, imperiling shorelines and waterfront property.
There's a failsafe: a hundred years ago, a seven-and-a-half mile wall was built to protect San Francisco from the waves, tides, and floods of the sea. The seawall allowed the city’s developers to fill in and build out the waterfront, paving the way for the vibrant commercial and cultural district that stands there today.
But as Forbes explains, the aging seawall has serious seismic vulnerability in the event of a big earthquake. The Port is one of a gaggle of city agencies working to plan and fund a seismic retrofit of the seawall—but with an estimated price tag in the billions of dollars, it won't be an easy task.
Quake, Not Sea Level, Is Biggest Threat To Seawall
Forbes told us that a major earthquake is her biggest concern for the waterfront.
Under conditions similar to those of the 1906 quake, the seawall would move three to five feet bayward, causing significant damage to the waterfront’s utilities, transit hubs, and historic bulkhead buildings.
In the worst-case scenario, a seawall breach could cause over $3 billion per year in repair costs, damaged buildings, lost tourism revenue, and other factors.
“We found that the seawall is not a very resilient piece of infrastructure, and it’s susceptible to pretty major damage in a big earthquake," Forbes said. "It's much more vulnerable than we guessed, because of the way that it was constructed on unreinforced soils."
And a big quake likely isn't far away. Scientists estimate that there's a 72 percent likelihood of San Francisco having an earthquake similar in strength to that of 1906 within the next 30 years.
“We’re overdue for an earthquake,” said Forbes.
But while improving the seawall's seismic resilience is "urgent" compared to the "patient problem" of sea level rise, Forbes would like to see both issues addressed simultaneously.
“As we tackle this earthquake problem, we need to wrap in what’s coming for the waterfront,” she said. “Sea level rise is something that we need to begin to grapple with, because if we don’t make it a now issue, it will be too difficult for our children to respond.”
But Laura Tam, the sustainable development policy director at the San Francisco Bay Area Planning and Urban Research Association (SPUR), said that the city will need to make an effort to increase public support if it wants the seawall retrofit to succeed.
“This project will likely to be disruptive to people,” said Tam, “and it’s likely to be very expensive. You can imagine putting that money into other projects that are considered urgent, such as housing or streets.”
“But because [the seawall] is such a critical piece of infrastructure in the city, it’s high time we devise a solution.”
Voter Support May Be Needed To Fund Project
Brian Strong, the city’s newest chief resilience officer, has been working on the city’s capital plan since 2006.
He’s currently trying to figure out how the city can pay for the cost of the seawall’s seismic retrofit, which is estimated at $2 to $3 billion. If the wall includes modifications to help mitigate the impact of rising sea levels, the price tag could rise to around $5 billion.
Even for emergency repairs that only address the most vulnerable sections of the infrastructure, the estimated cost will still be about $500 million.
Strong told us that a $350 million request for the seawall’s seismic retrofit has been included in the draft capital plan that will go to the city’s Capital Planning Committee tomorrow. The request will then go to the Board of Supervisors in early March before going to Mayor Ed Lee, who will have until May 1st to approve it.
If the Supervisors and Mayor Lee approve the request, it's likely that the $350 million general obligation bond will then go to voters as a potential ballot measure the next time we go to the polls in November 2018. It would require a two-thirds majority of voter support to pass.
Making Up The Difference: The Challenge Of Federal Funding
According to Strong, $8 million has already been set aside to study what the entire seawall retrofit project will eventually cost.
“We're committed to understanding what we're going to put before voters before it gets on the ballot,” he said. “That means being confident that we have the right schedule, the right numbers, and the right plan to make sure that the costs don’t go up later on.”
But even if the $350 million bond was approved by voters next year, it would be well below the $2-3 billion needed to reinforce the entirety of San Francisco’s seawall—let alone the $500 million needed to fix the most susceptible sections of the infrastructure.
“We’re looking at other [funding] sources as well,” Strong said. But he notes that the federal government usually doesn’t dish out money until after disasters happen—as was the case with Hurricane Katrina and Superstorm Sandy.
“We would love for the federal government to have a seismic or sea-level-rise program,” the Port's Forbes said. “But they’re just interested in current-day flooding.”
According to Strong, a finance working group (made up of city officials and members of the private sector) is currently vetting possible alternative sources of funding, including the Army Corps of Engineers, which helps to administer funds set aside by the Water Resources Development Act for projects that relate to flood protection.
The Port's Forbes also touted the Army Corps of Engineers as a potential partner to help retrofit the seawall.
“The magnitude of the seawall project is that it’s going to need funding locally, at the state level, and at the federal level to be successful,” she said. “There’s a federal interest in this [seawall] project because, with the king tides, they see the potential for flooding at the Embarcadero Muni station.”
Even though there is no seismic component to the Corps’ work, Forbes hopes that they’ll partner with the city to rebuild the seawall and protect San Francisco from flooding.
“When it comes to funding, we may be lucky that our seawall is susceptible to flooding—the only time I’d say lucky."