A San Francisco Bay Area highway project is raising questions about what it will take to fortify roads against rising sea levels.
Excerpt from this story from Grist:
Between the view, the marshes, and the birds, Liat Meitzenheimer concedes the drive along California State Route 37 is scenic. Still, she avoids it for two reasons: congestion and flooding.
The highway, about half of which is two-lane, is often backed up with people commuting between affordable communities in Solano County to the east and jobs in pricier Sonoma and Marin counties to the west. It also is a regional link to Napa Valley and other destinations, much of it built on embankments, bridges, and causeways that span marshes precariously close to San Pablo Bay. That makes it prone to flooding, which has led to occasional closures.
These problems will worsen as the population grows and climate change brings more frequent and intense storms. Without adaptation measures, portions of the road are at risk of permanent inundation by 2050.
The state Department of Transportation and the regional Metropolitan Transportation Commission are pursuing a $500 million project that would, over five years, remake portions of the 21-mile highway. It would replace one of five bridges with one 5 feet taller, raise two one-mile sections by up to 8 inches, add a carpool and bus lane in each direction, and restore a tidal marsh and other ecosystems.
Not everyone thinks that goes far enough. Some want the highway moved several miles inland. Others favor a far more ambitious $10 billion project that would take at least 20 years. It would raise almost the entire roadway, add a lane for cyclists and pedestrians, and perhaps include railway tracks. To do anything less, advocates of this approach say, overlooks two pressing issues.
“Highway expansion does not solve congestion and will worsen climate change,” said Zack Deutsch-Gross, who leads TransForm CA, a sustainable transportation advocacy organization. “This project is pretty egregious,” because the highway, if left where it is, “in the long term will be underwater.”
The challenges facing SR-37 are not unique. California’s iconic Highway 1, has been repeatedly closed due to floods, fires, and rockslides. Coastal cities like Miami Beach and Atlantic City are scrambling to harden infrastructure against rising seas and frequent inundation. Hurricanes routinely leave island and low-lying communities isolated by deluged causeways. Addressing these problems requires tremendous investment — bolstering bridges alone could cost $170 billion by 2050. Failing to do so could bring grave consequences. Without further adaptation, annual damage from coastal flooding worldwide could account for 2.9 percent of global gross domestic product by 2100. That’s up from 0.3 percent just 11 years ago.
