Alameda planners look at projected rise in sea levels
Peter Hegarty
Inside Bay Area
07/28/2011
With climate change projected to cause San Francisco Bay to rise more than 18 inches over the next 50 years, Alameda as an island could be especially vulnerable to flooding unless steps are taken to literally hold back the tide, local officials say.
The restoration of wetlands and the construction of levies and dikes will likely be among the ways used to prevent water cresting the shoreline, especially as the redevelopment of Alameda Point moves ahead.
But Alameda officials also say their response probably will evolve over time as new technologies emerge to combat the rising water levels and money is secured to pay for them.
The Bay Conservation and Development Commission -- which state lawmakers created in 1965 to help guide policy toward San Francisco Bay -- already has begun to address the issue by crafting a series of amendments in its overall plan for the bay.
While the City Council adopted a resolution in November that expressed concern that the amendments could undermine local authority on land use, the Planning Board on Monday urged the council to take another look at the document.
"The idea of rising sea levels does have implications for a lot of us here in Alameda," said Andrew Thomas, planning services manager with the city. "It's an issue that the Alameda community is sensitive to and is tracking."
Not only is Alameda an island that's flat, neighborhoods near Alameda South Shore Center have been built on landfill, putting them at risk as water levels change in the bay.
Meanwhile, Alameda Point has 1,444 acres -- equal to about one-third of the island -- and more than six miles of shoreline, which will make offsetting any rising sea levels a daunting task, local officials admit.
Other local cities, such as Hayward and Richmond, are expected to face similar challenges in the years ahead. And because of the shrinking polar ice caps, the bay's level will continue climbing even after the 18-inch mark is reached within a half-century, according to commission studies.
Along with changing waterfronts throughout the Bay Area, the rising sea levels will increase ground water, which will affect storm drains and cause other problems, said Jeremy Lowe of ESA PWA, an environmental consulting firm.
But Lowe also said local officials will not need an immediate solution since the increases will take place over decades. Still, he said, "we have some big decisions to make."
The effort to combat the changing environment at Alameda Point likely would include building sea walls, creating lagoons and using wetlands to lessen the impact of tides, Thomas said.
