Flooding and sewage overflow has been a hot button issue in New York City since Hurricane Sandy, inciting public and private programs to create new systems to help prevent future disasters. To address these concerns, a group of students and faculty at Pratt Institute has created the Open Sewer Mapping Project – an interactive map of New York’s sewer system that creates transparency and allows citizens and community groups to better understand its inner workings and problem areas. Supported by the Taconic Fellowship program, the data visualization effectively illustrates some of the sewage system’s most deficient areas in Newtown Creek, Tallman Island, Hunts Point, Jamaica Bay and Red Hook.



green design, eco design, sustainable design, Open Sewer Mapping Project, Taconic Fellowship, Pratt Institute, sewage overflow map, hurricane Sandy, waster water treatment plant

“We started Open Sewer Atlas NYC to make information about how the city’s wastewater and stormwater system more transparent and easier to understand,” said Josh Eichen, Planner/Manufacturing Retention Coordinator at the Pratt Center for Community Development, who served as the project’s faculty head. “NYC DEP has many publicly available documents and reports that detail out the system, but they are lengthy, complex, and difficult to find on their website. We wanted to take all the information that was out there, consolidate it, and display it in a way that was more accessible. We found that making this information interactive in the form of our web map and printed sewer maps helped demystify the system and make it more approachable for community groups and environmental advocates.”

With the interactive map, citizens (and potential designers and problem solvers) can see first hand just how the sewer system works. The map covers documented issues, as well as basic system functions coupled with data to illustrate the sewer’s ins and outs. On the map, viewers can find drainage areas for major sub sewersheds which are for larger overflows as well as drainage areas for combined sewer overflow which are for smaller areas during heavy rains.

Related: NYC DEP announces 6 super-soaking projects that will help prevent flooding and sewage overflow

“Sewer backups and street flooding happen all over the city, especially in low lying areas, but after speaking with different communities and researching ongoing projects we found that each area we looked at had unique sewer issues based on their geography and current infrastructure,” Eichen told us. “For example, in the Red Hook sewershed we learned that the wastewater from upland neighborhoods (Downtown Brooklyn, Prospect Heights, Boerum Hill, etc) was being conveyed downhill into Red Hook, then pumped back uphill to the wastewater treatment plant in the Navy Yard. During times of rain, combined stormwater and wastewater issues inequitably impact the downland neighborhoods of Red Hook and Gowanus because of these flows. The city has recently upgraded the Gowanus Pump Station to handle more flow and Flushing Tunnel which will divert wastewater / stormwater away from the sewer lines that run through the lowest lying parts of the sewershed. This upgrade may help reduce the amount of sewer backups and street flooding events in these areas.”

The map also indicates infrastructure elements like pump stations, outfalls and waste water treatment plants. Statistics for each feature are also outlined, including sewershed activity, wastewater treatment plant capacity, and gallons of stormwater discharged each year.

With the interactive map, which is easily accessible to anyone online, citizens and community groups can better understand the city’s sewer system and its environmental impact. The Pratt group has already partnered with several key organizations that can put the map to good use, but Eichen says that changing people’s attitudes about stormwater is the first step.

“Traditionally, stormwater has been treated largely as something that needs to be funneled down the drain and off the street as fast as possible. Water is a resource and if managed properly can provide real benefits to the city’s environmental quality. Green infrastructure realizes some of those benefits by absorbing water into natural systems that would otherwise be sent to the sewers. By doing so, water helps improve air quality, lower ambient temperatures, and improves aesthetics and ecology in urban areas.”

+ Open Sewer Mapping Project