San Francisco Mayor Ed Lee has proposed spending $8 million to find a solution to the earthquake-vulnerable sea wall that holds up the city's famed Embarcadero waterfront.
The decision, announced Wednesday, comes after new studies found the sea wall, which stretches from Fisherman's Wharf past the Bay Bridge to AT&T Park, could be shoved toward the bay by more than several feet in a massive earthquake, taking with it one of the city's most bustling areas.
The total cost of securing the wall has been placed at roughly $2 billion to $3 billion, but officials said the $8-million investment, while relatively small, is an important step to finding a solution to the problem.
"It's fantastic," said Patrick Otellini, the city's chief resilience officer, in an interview at the National Earthquake Conference in Long Beach on Thursday. "You're starting to see the city coming together from different departments and realize that the sea wall is a shared asset. This isn't just the port's responsibility."
The sea wall is something that many people aren't aware of. Built more than a century ago, its existence is taken for granted, yet is critical because it allowed San Francisco to extend its boundaries over the bay and provides flood protection.
The problem with the sea wall is not really the wall itself but the weak mud underneath it. In an earthquake, the artificial land behind the sea wall is expected to act like a liquid and press up against the sea wall.
That means the sea wall, while not expected to completely fail, could suddenly lurch toward the bay during an earthquake, damaging the wharves, piers, buildings and roadway above it.
Another problem is that some of the historic wharves — decks that extend the shoreline beyond the seawall — are supported by brittle concrete columns that could collapse in an earthquake. That poses a risk to buildings on top of the wharves and the finger-like piers attached to them.
The $8 million was proposed as part of the mayor's budget for the fiscal year that begins July 1, Otellini said.
"San Francisco has a history of solving our challenges through bold action," the mayor said in a statement. "San Franciscans built the sea wall a century ago, and it is our generation's turn to invest again to strengthen this critical piece of infrastructure."