These basketball courts double as a hidden flood defense

"They look like ordinary basketball courts. But two new courts built next to public housing in New York City double as flood prevention. In a sudden flash flood-when the city's aging sewer system can easily become overwhelmed and streets can fill with water-the sunken basketball courts act like retention basins. The design can hold as much as 330,000 gallons, with the court's lowest areas filling like a pool and additional water stored in bioretention cells beneath the surface."

"The project "becomes like a sponge, which basically holds the water as much as it can," says Runit Chhaya, principal at Grain Collective, a landscape architecture firm that worked on the design with city agencies, local residents, engineers from Hazen and Sawyer, and the urban planning firm Marc Wouters Studios. "It helps in not putting stress on the city storm system during a flood event.""

Two sunken basketball courts next to public housing in New York City function as flood-prevention retention basins integrated with recreational space. The courts capture flash-flood runoff and can hold about 330,000 gallons as low areas fill like pools while additional water stores in bioretention cells below. The design reduces load on the aging combined sewer system during extreme rainfall. The initiative began in 2017 with inspiration from low-lying cities' cloudburst strategies. Climate-driven increases in heavy storms and extensive urban pavement make combined-sewer cities like New York especially vulnerable. Large NYCHA properties enabled mitigation opportunities and resident engagement improved public-space outcomes.

Read at Fast Company