Weather in the Watershed
A watershed is an area of land that drains to a common waterbody, such as a stream, river, lake or ocean. Basically, you can describe any place as part of a watershed, because all areas of land drain to someplace. In our case, the Newtown Creek watershed is a highly urbanized area, and includes a vast industrial zone, major highways, cemeteries, parks, as well as several residential neighborhoods.
One defining characteristic of the Newtown Creek watershed is the sewer system. We are home to the Newtown Creek Water Pollution Control Plant (WPCP), one of New York City’s largest sewage treatment plants, that serves approximately one million residents within a 15,000-acre drainage area. Sewage is brought from this expanded area, treated and released at the WPCP. In this way, Newtown Creek has an additional area related to the watershed that we call the sewershed.
The map below shows the Newtown Creek sewershed that extends into Manhattan and our neighboring Bowery Bay sewershed in Queens, as well as the “natural watershed” area for Newtown Creek in green.

When the weather is dry, the plant has capacity to fully treat (to Clean Water Act standards) 310 million gallons per day and during weather, the plant can partially treat up to 700 mgd. When wet weather conditions exceed this capacity, the excess combined sewage and stormwater is released directly to Newtown Creek. This is called Combined Sewer Overflow. CSO damages the Newtown Creek ecosystem, and creates hazardous conditions for people on the water due to the pathogens that come along with untreated sewage. The area that contributes CSO to the creek is the green watershed area above.
In order to better understand how and when the sewers overflow, NCA is collaborating with the SWIM Coalition, Queens Public Libraries, Brooklyn Public Libraries, and the “dontflush.me“ project to install weather stations throughout the Newtown Creek watershed, with support from NYCEF Newtown Creek Fund (Hudson River Foundation) and Deutsche Bank Americas Foundation.
Map of Weather Stations in the Watershed
We want to estimate how much stormwater is entering the sewer system and when, and provide watershed residents with information about how wet weather impairs Newtown Creek. We can combine the rainfall data with what we know about the available capacity in the sewer system to create an alert system for sewer overflows. When the watershed is “on alert” we hope that watershed residents will hold off (within reason…) on flushing, since toilets in the watershed will flush directly to the creek when CSOs are occurring.
Meter of Sewer Levels…Is it Safe to Flush?
We created an alert for both Newtown Creek and Bowery Bay, because the creek has CSO outfalls from both of these sewersheds that are part of the watershed. At this point, the alert system is overly cautious, meaning that the alert will tell us “Don’t Flush” sometimes before CSOs actually occur. As we continue to refine the weather monitoring and our assumptions about sewer capacity, the alert will get better. One way we will calibrate the system will be to go actually look at a few key CSO pipes on the creek when the alert is telling us “Don’t Flush” and see if, in fact, CSOs are flowing.
Ultimately, we will also offer tools such as tweets and texts messages to particular users of the creek, such as boaters and waterfront workers, to alert them to potential pathogens in the water.


