Sherwood Design Engineers Submits Croton Plant Project

The award submission covers a water treatment plant built beneath Van Cortlandt Park that includes a green-roof golf course.

Updated on Nov. 6, 2026 in Environmental

Photograph of a constructed wetland with reed grasses and still water beside a stone-lined bioswale channel, framed by a tree line under overcast daylight. — Sherwood Design Engineers submitted its Croton Water Treatment Plant under Van Cortlandt Park for an award, a 290-million-gallon-per-day facility that supplies nearly a third of New York City's drinking water. AI Illustration. Upload story photo >

Sherwood Design Engineers submitted the Croton Water Treatment Plant project for an award in Van Cortlandt Park. The facility is a 290-million-gallon-per-day plant located about 300 feet underground that supplies nearly a third of New York City's potable water.

Why it matters

The project shows how groundwater pumped during deep excavation can be treated and reused on site rather than sent to the city sewer system. Its design addresses water supply infrastructure and stormwater management for the city's residents.

The plant's 290-million-gallon daily capacity and 300-foot depth are project specifications, with groundwater dewatering at about 55 gallons per minute during excavation. The submission does not report the award decision or measured performance since completion.

The players

Sherwood Design Engineers

Sherwood Design Engineers is the engineering firm that submitted the Croton Water Treatment Plant project for an award.

The details

The plant captures stormwater from the driving range and parking lots, along with bedrock groundwater pumped from 12 stories below grade. That water is routed through a perimeter of constructed wetland treatment cells and bioswales before reuse, eliminating site discharge into the city sewer.

Article on the Croton plant was published on enr.com on November 5, 2026.

Big Picture

The project applies constructed wetland treatment cells, typically used for landscape-scale filtration, to groundwater pumped during deep excavation for a municipal water plant. It extends that approach from stormwater management to the infrastructure that supplies potable water to the city.

Residents served by the plant receive water from a facility that reuses its own groundwater rather than discharging it to the sewer. The project's wetland-based stormwater capture is a design approach other municipal projects may adopt.

The takeaway

Deep infrastructure projects can turn groundwater that must be removed during construction into a resource for treatment and reuse. The Croton design shows that a water plant and a public green space can share one site.