New York Needs to Get Spongier—or Get Used to More Floods
Sourced from Wired
TWO YEARS AFTER the remnants of Hurricane Ian dumped up to 10 inches of rain on New York City in just two hours, the metropolis is once again inundated today by extreme rainfall. It is one of the many cities worldwide grappling with a counterintuitive effect of climate change: Sometimes, it will get wetter, not drier.
On a warming planet, it’ll rain more and individual storms will get more intense. This pain will be especially acute in urban areas, which are built on stormwater infrastructure designed to handle the rainfall of yesteryear. Think back to what the builders of the last century wanted: sewers and canals that funneled rainwater as quickly as possible into a river, lake, or ocean, before it had a chance to accumulate. That worked fine, most of the time. But over the intervening years, rare catastrophic flooding has been growing more common. Ancient wastewater systems are now tasked with getting rid of ever-bigger inundations.
Today’s concrete- and asphalt-heavy cities are also now a kind of seal atop the landscape. They have lots of hard surfaces like roads and parking lots, and maybe only a smattering of softer surfaces like parks. Because they are impermeable, water can’t sink into the ground—it has to rage across town, turning subway stairs into waterfalls and swamping schools.
Better sewer systems will be indispensable, sure, but planners are also fundamentally reimagining urban areas as “sponge cities” designed to mitigate flooding by absorbing water. Clearly, NYC still has a ways to go in terms of flood management. But the city now has more than 12,000 green infrastructure assets across the city, said Edward Timbers, spokesperson for the NYC Department of Environmental Protection, in a statement provided to WIRED. This includes rain gardens, or strips of roadside greenery that absorb rainfall, and blue belts, or conserved natural drainage systems like ponds and wetlands. All that green infrastructure helps keep rainwater out of the sewage system.
From the Living Architecture Monitor
