NOVATO, Calif. (KGO) — Parts of the Bay Area that have long faced flooding risks could face additional threats this winter, as experts monitor a combination of factors including El Niño, sea level rise, king tides and warming ocean conditions.
Nonprofit leader Shannon Parkhurst is among those working to help residents prepare. Visiting a Novato intersection that was submerged during historic El Niño flooding in 1982, she highlighted the area’s vulnerability.
LIVE UPDATES: High tides continue to submerge parts of the Bay Area and further flooding is expected
“If you look around, believe it or not, every one of these houses you see has been underwater,” Parkhurst said.
Parkhurst nonprofit the Lemon Aide Project is helping neighbors prepare for potential flooding this winter. At the same time, climate scientists and planners in the Bay Area are assessing the severity of the flood’s consequences.
Experts are monitoring several factors, including potentially wetter storms associated with El Niño, higher tides caused by rising sea levels and main tide cycles, and Kelvin waves, which are warm, expanding masses of ocean water.
MORE: How El Niño affects high tide flood advisories along the California coast
A coastal flood advisory has been extended through Friday throughout the Bay Area as El Niño factors contribute to high tides, causing flooding along the California coastline.
“This happens when the water at the equator warms and pushes a sort of water bulge along the California coast,” said Dana Brechwald, deputy director of planning for climate adaptation at the San Francisco Bay Conservation and Development Commission.
The commission helped develop maps that project the potential impacts of warming ocean temperatures and rising tides, helping to establish baseline estimates for future flooding scenarios.
“We will see about 12 inches of total additional water level due to thermal expansion,” Brechwald said.
Brechwald said the maps are intended to help cities and counties plan for a range of scenarios while also providing residents with information about potential risks.
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California could feel significant impacts from the return of El Niño, a weather phenomenon linked to some of the state’s most memorable winter storms.
Areas identified as particularly vulnerable include low-lying, levee-protected sections of the Marin County coastline, portions of the Peninsula and South Bay communities such as Alviso, as well as significant stretches of the East Bay coastline including Alameda and the Oakland Airport.
“You can see there’s a lot of overruns at the airport and flooding in this residential area,” Brechwald said.
For many residents of flood-prone areas, the king tides that caused this month’s flooding could provide a glimpse of how sea level rise and El Niño-driven storms could combine to create additional challenges this winter.
MORE: El Niño winter: Bay Area airports face risk of holiday flooding, research finds
Organizations such as the Lemon Aide Project encourage residents to prepare emergency kits and evacuation plans in advance of possible flooding.
“I want people to realize that things could be really, really bad,” Parkhurst said.
Residents interested in exploring flood risks in their communities can access interactive maps through the San Francisco Bay Conservation and Development Commission website. Additional information on preparedness efforts is available through the Lemon Aide Project.
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