By Lise Alves, Contributing Reporter
MIAMI BEACH, FLORIDA – Many coastal cities in the U.S. and around the globe face threat from sea level rise (SLR). A recent study by the U.S. Geological Survey shows that the effects of sea level rise in areas around San Francisco Bay could be more disastrous than previously thought, impacting over 600,000 residents.
“About two-thirds of California’s most vulnerable areas are in the San Francisco Bay Area, according to a recent study by USGS scientists,” explains Kristina Hill, Associate Professor at the University of California, Berkeley.
“A recent UC Berkeley study estimated that seventeen percent of job-dense areas, fourteen percent of transit corridors (by area), and eleven percent of so-called ‘priority development areas’ (where new housing is planned to go) are vulnerable to six feet of SLR,” adds Hill.
According to the professor, forecasts call for a sea level rise of three to six feet by 2100, ‘but we are also aware that ten feet is possible’.
Rising groundwater is likely to increase this vulnerability, says Hill, creating flooding and infrastructure problems for 25 to 50 percent more land area than saltwater flooding would alone. But according to Hill the region is fighting back and already has the world’s most ambitious plan to restore almost 100,000 acres of lost wetlands.
“People have voted to tax themselves to support this effort because it will also help to delay the impacts of sea level rise,” she says. However it is not the whole solution, says Hill noting that there are projects of new developments on raised land underway, such as Mission Rock and Treasure Island in San Francisco and Brooklyn Basin in Oakland.
“But you can’t raise everything. So, we’re starting to talk about the potential for floating urban districts, like what the Dutch are experimenting with,” she says noting that these floating districts would be constructed inside of levee protections, not on the Bay itself.
Pumping groundwater is another option, but the professor says relying on pumps, levees and even learning to live with higher sea levels are not the optimal solutions. “Our groundwater rise problems will only get worse if we pump and then the land subsides, so I think that pumping and levees are limited strategies here,” she concludes.
There are other problems too. According to Hill, the Bay areas’ most vulnerable urban districts rest on old wetland soils, such as San Rafael’s canal district, East Palo Alto, East Oakland and Marin City.
These high-risk flooding regions detain housing for lower-income families and workers, with local population registering a high percentage of communities of African-Americans and Latins.
“But they are also home to the corporate campuses of Facebook and Google, and several key segments of highways that tie the region’s economy together. Also, our two primary airports are likely to experience early flooding problems – on runways and on access roads,” she argues.
For Hill the current urbanization structure in the Bay area makes it harder to find solutions without interrupting flows of traffic and air travel, and without displacing poorer communities.
“But we also have a housing crisis that has created great demand for new housing, and that demand may help us build our way into adaptation, incorporating safe new housing, at mixed price levels,” she says.
According to Hill, the Bay area has always had a reputation for technological excellence. Now, she says it is putting drive for excellence on sea level rise.
“We’ve taken a very ambitious approach to using wide wetlands as a way to reduce wave energy in the north and south Bay,” concludes the UC-Berkeley professor.