top of page
  • SWIM

The City's Largest and Most Complex CSO Long Term Control Plan is Finally Underway!

Updated: Apr 21, 2021

Map of the Waters This Plan Will Impact

After postponing the Citywide Open Waters CSO Long Term Control Plan twice in recent years, the City is finally getting the plan underway. We wrote about the postponement last year here. And here is a link to our public comment letter to the State which outlines the public's expectations for this plan.

This plan will impact the health of NYC's waterways for generations. The City really needs to get this one right!

On April 16th NYC DEP held a public meeting to provide preliminary information about their modeling and analysis for the plan. Stakeholders had a lot of questions about how DEP is defining "attainment" with the Clean Water Act standards for safe swimming and fishing in these waters. Here is a list of questions we've asked City officials about their water quality sampling and the modeling they are using to inform this plan. We'll post their answers here as soon as we receive them. Here is a link to the City's presentation document from the April 16th meeting.


According to the NYC Panel on Climate Change, our region can expect to see a 1–8% increase in precipitation by the 2020s, and 4–11% increase by the 2050s.

DEP is using rainfall data from 2008 to model water quality conditions in anticipation of climate change. We’re already seeing rainfall patterns exceeding that rate; the 2018 sampling season was 14% rainier than 2008.

More precipitation means more Combined Sewage overflows over the next few decades while the City updates the combined sewer system and installs green infrastructure solutions.


Below is a screen grab of all the City's sewer outfall points along the waterways that this plan will impact. This map is housed on the Cut the Crap NYC! website recently launched by Hudson Riverkeeper, NRDC and Save the Sound. You can zoom in on each outfall on the map to see how much CSO volume discharges from that outfall every year and how many events per year take place at the point. You can also see which City Council District the outfall is in so that you can talk with your City Council member about how important it is for them to be aware of the City's plan for the outfalls in their district and what's going in the waterways.

Be sure to stay in touch with SWIM Coalition to get updates on this important plan and keep your elected officials informed of the developments as the plan progresses. We'll need your support at the September 2019 public meeting and on sending public comments to the State about your specific concerns.

45 views0 comments
bottom of page