Tackling Sewer Overflow in the Bronx: Green Solutions for Spuyten Duyvil Creek

July dumped more than twice the Bronx’s normal rainfall, overwhelming the borough’s century‑old sewers and flushing untreated wastewater into rivers and creeks.

Along the Spuyten Duyvil waterfront, each downpour releases a murky gush from a combined sewer pipe by the Spuyten Duyvil Creek — a recurring reminder of the city’s sewer overflow problem and the stakes of Bronx Community Board 8’s top environmental and sanitation budget request for 2026.

The board wants a living shoreline and green infrastructure along Department of Environmental Protection easements to “mitigate combined sewer overflow outfalls into Spuyten Duyvil Creek adjacent to Spuyten Duyvil and Marble Hill Metro North stations.” 

It is a local fix to a citywide problem, one that environmental advocates say extreme weather events will further exacerbate.

About 60 percent of New York’s sewer network is “combined,” carrying both household wastewater and stormwater in the same pipes. In dry weather, the mix flows to one of 14 treatment plants. 

“The kind of rain that we’re getting is deluges,” said Jodie Colón, a longtime steward of the Spuyten Duyvil shoreline. “We’re supposed to get 1.25 inches in an hour. The system can only handle about two inches in 24 hours, so it doesn’t take much to kick it out.”

When heavy rain falls, more than 1.5 inches an hour, the system can’t keep up. Gates open automatically to divert the untreated overflow into nearby waterways to avoid flooding streets, basements and treatment plants.

The outfall is hard to miss at Shorefront Park, a marsh‑edged strip between the Henry Hudson Bridge and Amtrak tracks. Colón says the initial burst after a storm is the worst.

“You can literally see it –  the big plume coming out into the water,” she said. “The first flush usually has a lot of garbage in it.”

The combined system was built in an era of smaller populations, different rain patterns and looser water‑quality rules. 

But July’s series of torrential storms tested the limits, sending brown surges into the Spuyten Duyvil Creek, which feeds into the Harlem River.

Karen  Argenti, of the Bronx Council for Environmental Quality (BCEQ), said the budget request fits into a broader vision: using nature‑based designs to buffer the Harlem River shoreline, filter polluted runoff and protect against storm surges. 

 “Nature‑based solutions are cheaper and actually better for the environment,” she said.

Living shorelines use wetlands, native plants and natural materials, like seashells, to absorb wave energy, prevent erosion, and filter pollutants. In Spuyten Duyvil, advocates imagine a narrow vegetated fringe that could clean water and blunt the wakes from passing boats, which stir up sediments laced with contaminants.

“Shorefront Park is already a living shoreline in the form of the wetlands,” said Robert Fanuzzi, BCEQ’s president. “If it were landscaped and designed properly to capture water, it would actually serve as a filtering system for any runoff before it enters the canal.”

Colón sees the budget request as one piece of a layered approach. 

“You can mitigate this in multiple ways,” she explained. “You can do it at the end of the pipe, and you can catch it before it even gets into the sewer system. That’s what green infrastructure is.”

The DEP reports its green infrastructure program, utilizing elements like rain gardens, bioswales, and permeable pavement can capture stormwater before it reaches the sewer – easing capacity and cutting overflow.

There is also a policy fight over water‑quality standards.

The state Department of Environmental Conservation has proposed reclassifying the Harlem River to “Class SB (wet weather limited use),” which would suspend swimming and other primary contact recreation for 36 hours after a half‑inch or more of rain. 

Evironmentalists see the reclassification as lowering the bar. 

“They’re saying, ‘Oh yeah, it’s swimmable – just not if it rains,’” Colón said. “We think it should be clean to the point where it meets the swimmable criteria year‑round.”

Fanuzzi worries the policy could normalize sewage discharges.

“Even with daylighting [Tibbetts Brook], we are still failing to have a clean river protected from combined sewer overflows,” he said.

The Tibbetts Brook daylighting project, scheduled for completion in the next decade, will divert stormwater from the combined system into a new channel flowing directly to the Harlem River, freeing sewer capacity. It is the largest green infastructure project DEP has undertaken this year, according to the agency. 

It also reports it will keep more than 215 million gallons of water out of the sewers each year.

 But other outfalls along Spuyten Duyvil Creek will remain, still discharging untreated wastewater during storms. They are likely to keep running during significant rain events unless major investments are made.

“The more rain, the more overflows,” Colón said. “We think this is how the city could take the next steps in making the water cleaner and more resilient.”

Colón has been watching that plume for nearly 30 years, and still comes out in the rain with a camera to document nearly every event. 

“We must stop the water from coming out of this pipe,” she said, emphasizing to The Press.