Tag: NYC

Standing near the edge of the Harlem Meer this week, NYC’s Mayor Zohran Mamdani framed an ambitious underground civil engineering project in an unexpected way. Evoking the animated lore of Avatar: The Last Airbender, he introduced the city’s newest infrastructure overhaul as an act of civic waterbending: steering the flow of water across urban landscapes to serve and protect neighborhoods rather than swamp them with flood waters during storms.

For over 160 years, New Yorkers have seen Central Park as a scenic sanctuary—a place to wander wooded trails, watch seasonal and resident birds drift across calm ponds and soar from tree to tree, and take refuge from the city’s busyness.

Yet behind that tranquil landscape lies an ongoing operational dilemma:

1. To keep the north end water bodies full during dry spells, the city continually pumps in roughly 175 million gallons of municipal drinking water every year.
   
2. When severe storms hit, heavy runoff cascades off park terrain and adjacent streets, overwhelming local storm sewers and forcing floodwaters into basements, subway entrances, and avenues across Central and East Harlem.

The newly launched $35.7 million North End Recirculation Project transforms this 19th-century scenic retreat into an active, protective stormwater sponge.

The Unseen Problem: Drinking Water In, Storm Sewage Out

Frederick Law Olmsted and Calvert Vaux shaped the northern park waterways between 1862 and 1865, creating three interconnected bodies of water: The Pool, The Loch, and The Harlem Meer.

While these ponds look natural, their levels are maintained by the city. Every year, Central Park draws an estimated 175 million gallons of clean municipal drinking water simply to keep those ponds replenished.

Meanwhile, extreme rainfall events are increasing across New York City. The surrounding combined sewers can’t manage that sudden deluge. Runoff rapidly fills the Meer to capacity, backing up local drainage lines and forcing sewage-laden water into street intersections and ground-floor homes along the park’s boundaries.

Treating park water bodies purely as decorative scenery wastes clean drinking water during heatwaves and floods neighbors during storms.

How Central Park Acts as a Living Sponge Works

Rather than excavating massive subterranean concrete holds, the project uses the natural slope of Olmsted’s original layout across a 204-acre watershed.

• Closed-Loop Recirculation: During dry periods, water from the Harlem Meer is continuously pumped back up to the top of The Pool, flowing downhill by gravity through The Loch and back into the Meer. Natural filtration keeps the water clean and circulating, eliminating the need to top off the ponds with city tap water.
  
• Protective Catchment: When meteorologists forecast a heavy storm, park managers will lower the water level of the Harlem Meer in advance so it can take on the extra water and keep it in the park rather than flood the surrounding streets.
  
• The Neighborhood Benefit: By temporarily draining part of the Meer, the city creates a vast empty space right before the storm. Rainwater from park hills and surrounding streets surges naturally into the Meer instead of rushing into neighborhood storm drains.

Once the storm passes, the captured water is filtered and recirculated, keeping 132 million gallons of stormwater out of neighborhood sewers every year—a massive 90% drop in sewer runoff from this watershed.

Environmental Justice at the Park Boundaries

Resilience infrastructure must protect the communities that face the greatest risk.

For years, East Harlem residents and advocates from organizations like WE ACT for Environmental Justice have highlighted how low-lying northern Manhattan streets bear the brunt of storm waters. Basement apartments flood, street corners become like impassable lakes, and sewer overflows dump untreated waste into open waterways and onto the streets.

By reimagining Central Park not just as a respite (which it certainly is!), but also as protective green infrastructure for Central and East Harlem, this project proves that green spaces can do the heavy lifting to help people as climate change intensifies.

The Togetherhood Takeaway

Every public green space can play an active defensive role against extreme weather.

• Rethink Decorative Water: Examine ponds and decorative fountains in your neighborhood. Advocate for retrofits that replace tap-water top-offs with recirculating, naturally filtered systems.
  
• Demand Dynamic Infrastructure: Storage basins should not sit full during storms. Urge city managers to install smart valves and retention ponds that empty ahead of storms to catch neighborhood runoff.
  
• Connect Park Boundaries to Community Needs: Beautiful parks should never be disconnected from the streets around them. Ensure public investments protect adjacent neighborhoods from runoff and sewer back-ups.

When we turn greenspaces into allies and collaborators, we save our drinking water, protect homes and businesses, and maintain the health of all beings who live in our communities.