New York City proposal would require rainwater detention tanks for new development

A proposal under consideration in New York City would require developers to install a rainwater detention tank on many new projects within the city limits.

The rule would apply to projects on lots sized 20,000 square feet or more in designated drainage areas. It would require developers to install a detention tank that could capture more than the stormwater volume of a 10-year rainfall event.

There would be a one-inch maximum diameter for the detention tank’s orifice, where water would exit, in order to create greater retention and a slower release of stormwater. This strategy was created after the city shifted away from the idea of creating separate sewer lines.

City officials rejected separating stormwater and wastewater lines because that massive public works project would have been too costly and would have taken too long to implement.

New York City has two very large buildings dedicated to answering the 911 calls of its five boroughs. With more than 11 million emergency calls annually, it makes perfect sense. The second of these buildings, the Public Safety Answering Center II (PSAC II) is located on a nine-acre parcel of land in the Bronx. It’s an imposing 450,000 square-foot structure—a 240-foot-wide by 240-foot-tall cube. The gleaming aluminum cube risesthe equivalent of 24 stories from behind a grassy berm, projecting the unlikely impression that it might actually be floating. Like most visually striking structures, the building has drawn as much scorn as it has admiration.