As receding floodwaters left a high-tide ring along the Embarcadero Monday, Port of San Francisco officials were finalizing plans for a public forum tonight at the Ferry Building — a community meeting on how to defend the same stretch of waterfront from the sea.

The weekend's king-tide flooding, which the National Weather Service warned will continue through Wednesday, is exposing a gap city leaders have so far addressed mostly in studies: San Francisco voters approved a $425 million seawall bond in 2018, but a joint analysis by the Bay Conservation and Development Commission and the Metropolitan Transportation Commission puts the price of regional shoreline protection for the entire Bay Area at $96 billion. Scientists say the flooding is not a one-time anomaly — it's a preview.

The Embarcadero flooded over the weekend as a combination of El Niño conditions, unusually warm Pacific Ocean waters, and elevated king tides pushed water levels above normal along the waterfront. San Francisco International Airport and the Embarcadero were identified by city officials as among the most vulnerable low-lying areas in the city.

Michael Beck, director of the Center for Coastal Climate Resilience at UC Santa Cruz, said the drivers behind the weekend event are the same ones that will amplify coastal flooding in the months ahead.

"Our waters off the Pacific are warmer than usual, and this is likely to drive some very significant storms even throughout the winter," Beck told ABC7. "So, what I would say right now is, this gives us a bit of a prelude to what we could be seeing even more of with higher levels during the winter, if these high tides are coupled with some storms that could be stronger and more frequent than normal."

Beck was direct about the long-term trajectory. "It is going to get worse, and we need to start preparing for the fact that it is going to get worse," he said. "There are some places which we are going to have to invest in more protection. There are some places where we can still rely on wetlands, and wetlands coupled with our levies, to reduce some of these risks in the future."

San Francisco Supervisor Danny Sauter acknowledged that the city's existing commitments barely scratch the surface of what's required. "Long term, we need to build up our seawall," Sauter said. "The voters in 2018 approved a bond to start that work. This is work that's going to take decades. It's going to take billions of dollars. The voter-approved bond was $425 million. So, it gets us started."

The regional picture is significantly larger. Larry Goldzband of the Bay Conservation and Development Commission said the agency partnered with the Metropolitan Transportation Commission on a comprehensive cost estimate for Bay Area-wide protection. "We looked at all the proposed projects and then we looked at places without proposed projects and figured what would actually fit there," Goldzband said. "And we used that modeling to come up with $96 billion."

The gap between $425 million and $96 billion has not gone unnoticed at the Port of San Francisco, which operates the Embarcadero waterfront and is already running an active Waterfront Resilience Program. The Port's own planning documents project that the city must prepare for three to seven feet of sea level rise by 2100 — a range that would permanently alter the character of the downtown waterfront.

The Port is running two active projects: the Downtown Coastal Resilience Project and the South Beach Coastal Resilience Project, both of which are currently seeking public input through a survey open until July 17. Tonight's community open house, scheduled for 5:30 to 7:30 p.m. at the Ferry Building Grand Hall, is focused specifically on the Downtown Coastal Resilience Project — the stretch of waterfront that just flooded.

Officials and scientists alike are framing the current event as a forcing function. Flooding driven by the current conditions is expected to persist through Wednesday, even without additional storms in the picture. The harder question — who pays for the $96 billion the Bay Area actually needs — has no answer yet.