Elena Shao, INSIDE CLIMATE NEWS
Infrastructure experts in the San Francisco Bay Area have begun replacing impermeable roads and stormwater drains with water gardens and restored marshlands.
As an environmental officer in Samoa, Violet Wulf-Saena worked with the Lano and Saoluafata Indigenous peoples to restore coastline mangrove ecosystems that could slow incoming waves and protect communities from storm and flood damage.
Two decades later, in California’s San Francisco Bay Area, she’s the director of a nonprofit called Climate Resilient Communities that works on the same issue: restoring marshlands and wetlands to better protect vulnerable neighborhoods in low-lying areas from sea level rise.
Some areas of the Pacific Islands, where Wulf-Saena grew up, are projected by conservative estimates to see the sea level rise 10 inches by mid-century. By then, East Palo Alto, about 30 miles south of San Francisco, where Wulf-Saena works now, may also be frequently underwater during high tide events.
“Nature is the best protection to sea level rise, and if we restore these ecosystems we can mimic a lot of that protection,” she said. “It can be like a sponge.”
Most aspects of the built environment in the modern city are designed to drain away water as quickly as possible. Rain slides off of roofs, over concrete and asphalt and down into sewers, where it’s then redirected to the sea, lakes or rivers. The traditional approach to large water events like floods and storm surges has been to engineer the water out of the way, using seawalls, levees and flood barriers.
This means that cities like San Francisco could face billions of dollars in flood and storm damage as climate change worsens and overwhelms that infrastructure, all without capturing and reusing a lot of that water, which could ease some of California’s periods of drought.
Now, infrastructure experts are pushing for urban spaces to be reimagined as sponges—not just by restoring marshlands, but also with more parks and gardens soaking up stormwater, pebbles underneath surfaces acting as natural filtering systems and a more porous type of concrete absorbing water and slowing it down.