Climate-Change Denial in Alameda
As sea levels rise, the Island will face the most serious flooding in the East Bay. But officials have been slow to float sustainable solutions.
Experts say coastal communities built on fill, like much of Alameda, are more vulnerable to flooding during high tides and heavy storms.
Photo by D, Ross Cameron
(page 1 of 4)
Paul Beusterien noticed water seeping through cracks in a seawall on Alameda’s Bay Farm Island. It was Christmas Eve 2015, during a king tide, when the moon was full and the ocean had reached its highest levels of the year. Saltwater pulsed through the seawall that flanks Veteran’s Court, a cul-de-sac west of Bay Farm Bridge, off Island Drive. The seepage streamed onto the road and disappeared into a storm drain below the Harbor Bay Club.
Observers gathered on the shoreline to see just how high the tide would go. Beusterien, who was monitoring the wall as vice president of the Community of Harbor Bay Isle Homeowners Association, which represents the concerns of 2,973 homeowners on Bay Farm Island, wasn’t surprised by what he was seeing. “I’d been to Veteran’s Court at some point during a big storm before, and at one point I saw the seawall leaking in the middle,” he explained. Still, Beusterien was concerned.
Veteran’s Court was once the on-ramp to an earlier version of the Bay Farm Bridge. Today, it dead-ends in a concrete platform that juts over the San Leandro Channel, north of the modern bridge. The platform is the perfect spot for fishermen to cast lines into the narrow channel that connects San Francisco Bay to San Leandro Bay. But when storms coincide with king tides, the ocean overtops the fishermen’s platform, and the seawall seepage intensifies.
Beusterien, however, was more worried about erosion along Bay Farm’s northern shoreline. “When you walk along the north shore, you see erosion in multiple places,” he said.
Unlike Bay Farm’s western shoreline, which is heavily armored with large boulders known as “riprap,” the north shore has low areas that are vulnerable to flooding. During another king tide event in December 2016, a large wave crashed across the levee, leaving a puddle of sand-filled water on the berm. “The water level was slightly higher last year, but there’s more water flowing this year, and there’s more erosion along the shoreline,” Beusterien said. Luckily, the rain held off that day, and, within 30 minutes of the high tide’s peak, leaks through the seawall and across the levee subsided.
But in January, a powerful king tide left even more puddles on the levee path, startling a snowy egret, which flew up, long legs trailing, then relocated on drier ground. A pair of coots paddled along the increasingly swollen shoreline, navigating debris that the king tide had dragged up: innumerable shards of plastic, beer cans, vodka bottles, a Frisbee and a tennis ball, fast-food wrappers, more plastic, a quart of butane lighter fuel, a child’s plastic chair, and a steering wheel cover. This unsavory trail was an ugly reminder of what scientists have been warning for decades: that many human activities increase atmospheric concentrations of heat-trapping gases, causing the planet to warm. Rising temperatures, in turn, warm the oceans, which expand as temperatures increase, causing more polar ice to melt and adding more volume to the oceans.
But even though it’s increasingly evident that climate change and sea-level rise are putting many coastal communities at risk, Alameda has yet to forge sustainable solutions.
Photo by D. Ross Cameron
Paul Beusterien points out a place where the seawall near his home is prone to leaking.
“See, there’s a gap here in the levee,” Beusterien said, stopping to identify a weak point in the levee—a low spot in the berm that protects the north end of the island’s northernmost lagoon. As the only guard to the lagoon’s entrance, the low berm engenders fears about what would happen to homes that surround the lagoon if king tides and heavy storms pound the area simultaneously and send bay water inland. “So we need to follow through on studies to maintain the shoreline and protect homes from increased flood risk,” Beusterien said, as wind whipped the offshore waves under gray skies that threatened to dump more rain.
He’s not alone in his concerns. In 2009, the U.S. Army Corps of Engineers reported that high waves, associated with storms in December 2005 and January 2006, damaged Bay Farm’s northern dike, incurring $500,000 in emergency repair costs. According to the Army Corps’ study, storm events such as that one have a 5 percent chance of occurring in any given year.
In addition, the Federal Emergency Management Agency in recent years has been rolling out flood-zone maps to coastal communities throughout the country, identifying increased flood risks. In 2015, FEMA identified several such zones on Bay Farm Island and parts of Alameda’s main island. According to the city of Alameda’s analysis of these maps, 2,000 parcels of property in Alameda reside within what FEMA considers to now be the 100-year floodplain.
“That means there is a 1 percent chance that in any one year, the property will experience flooding from extreme high tides and storm activity,” city officials warned in a letter mailed to hundreds of Alamedans in the fall of 2015. Ultimately, FEMA’s estimates suggest that these areas could experience 1 foot to 3 feet of flooding.
“History has shown that if portions of Alameda flooded in the past, there’ll be flooding in future,” said Eric Simmons, a regional engineer with FEMA, during a presentation to Alameda homeowners. Simmons added that “water levels in the bay have elevated by more than 8 inches in the last century.
“Coastal flood risk is great and only getting worse.”
Indeed, climate experts predict that sea-level rise during this century will heighten the threat of flooding for coastal communities like Alameda. Last year was Earth’s hottest on record for the third consecutive year. And according to the most recent research, climate experts say sea levels could jump by as much as 8 feet by 2100 as ice sheets in Greenland and Antarctica sheer off and splash into the ocean.
However, climate experts also note that there’s a major flaw in FEMA’s mapping approach: It doesn’t consider projected sea-level rise as a factor in determining flood zones. Instead, the agency only takes into account past flooding and current sea levels in its maps. Consequently, there likely will be far more areas in danger of flooding in Alameda during the decades ahead.
“All the agencies involved in coastal management and planning should be looking at sea-level rise,” said Matthew Heberger, a senior research associate with the Oakland-based Pacific Institute.
Yet despite dire warnings, the city of Alameda is struggling to seriously address the threat of flooding—or sea-level rise—except at Alameda Point. The city instead has decided to appeal FEMA’s flood maps, contending that Alameda’s problem is not as bad as the federal agency says. In addition, some Island residents have latched onto a conspiracy theory: that FEMA is purposely overstating the flooding threats in order to coerce more property owners into buying insurance.
By contrast, across the bay, Foster City, another low-lying coastal community, has taken a proactive approach. That city has set aside tens of millions of dollars on flood-control projects and expects to finish addressing many of its flood risks in the next few years.
FEMA has also been studying flood hazards for other sections of the San Francisco Bay Area, including portions of Oakland, Emeryville, Berkeley, and Richmond. The agency has sent draft flood maps to all these communities and to the rest of the Bay Area. So far, the maps have been finalized in Marin, Sonoma, Napa, Solano, and Contra Costa counties. In Alameda County, where the maps are still a work in progress, Alameda and the Port of Oakland appear to face the most serious threats. “The San Francisco Bay shoreline in Oakland and Berkeley is steeper and less flood prone than the shoreline in Alameda,” Simmons explained.