Mapping Gowanus

Combined Sewer Overflow Point Gowanus Watershed Gowanus Sewershed

Combined Sewer Overflow (CSO) Points

New York City has a combined sewer system. The sewer pipes leading from our houses and businesses are connected to the pipes that drain rainwater from the street. When weather conditions are dry, the raw sewage flows to the Red Hook Wastewater Treatment Plant (located at the Brooklyn Navy Yard). But during a rainstorm, the rainwater is added to the sewer system causing it to overflow. The mix of rainwater and sewage is released into the Gowanus Canal at the 18 Combined Sewer Overflow (CSO) points, indicated on this map.

Gowanus Watershed

A watershed or drainage basin is an area of land where the surface water drains into the same place at a lower elevation. The Gowanus watershed is 6 square miles and includes the Carroll Gardens and Park Slope neighborhoods.

Gowanus Sewershed

The Gowanus sewershed is the point where all of the neighborhood sewers combine and are either flow to the Red Hook Wastewater Treatment Plant or overflow into the canal.