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Wappingers Falls Stormwater Wetland

Description

view of the construction of a stormwater wetland. pit in ground is dug out and being filled with special materials

The Village of Wappingers Falls and other communities in the Wappinger Creek watershed have been concerned about water quality for many years. Wappinger Lake is a man-made reservoir formed on Wappinger Creek that serves as a significant source of groundwater recharge for the Village's drinking water wells, recreation and wildlife habitat. The water quality had been decreasing steadily in recent years, primarily due to sediment deposition and associated nutrient loading. Building on prior studies, a gravel filter wetland treatment system was built at critical outfall points, to both manage and treat stormwater runoff before it reached critical loading points in the watershed.

This installation is located at in infill site in the Village that had experience repeated flooding during major storm events. The site was an existing drainage swale with a large outfall directly to the lake.

view of completed stormwater wetland. there are two pools of water and a marshy area

The system has four treatment stages that include a sediment forebay, gravel wetland filter, shallow wetland system and an outlet pool. Sub-surface flow gravel wetlands can trap and treat 85-95% of sediment and suspended solids.The permanent water level is maintained just below the surface of the stone and vegetation with an adjustable standpipe system. Stormwater is physically filtered as it passes through the stone, and biologically treated through plant uptake and soil microorganism activities. The biological treatment continues on the volume of water that remains in the wetland even after the storm has passed.

The wetland has an impervious liner to ensure no contamination of native soils. Accumulated sediment is flushed and captured for safe disposal, enhancing treatment and extending the life of the system.

Site Location

  • Site Name: Wappinger Falls Ecological Stormwater System, Southern Dutchess News
  • Address: 84 Main Street East, Wappingers Falls, NY 12590
  • Owner: Southern Dutchess News, with permanent easement to Village of Wappinger Falls
  • County: Dutchess
  • Watershed: Wappinger Creek
  • Land use of site: Municipal
  • Can this site be visited? Yes, but call first to arrange
  • Location on site: Behind Southern Dutchess News building

Practice Details

  • Intent of design: This practice was designed to provide flood resiliency using retention ponds, while providing significant water quality improvement using a unique gravel filter wetland design to trap and remove up to 95% of the sediment passing through it. Wappinger Lake is considered impaired for phosphorus, aquatic vegetation, and sediment; suspected sources include stormwater runoff.
  • Size of structure/capacity: 0.9 acres
  • Size of drainage area: 240 acres
  • Plants or materials used: Native plants are used on the wetland surface, and four layers of engineered stone act as a filter
  • Maintenance: Flushing twice annually, routine inspection for invasive species, signs of erosion, or washout
  • Maintained by: Village DPW and consulting PE will monitor, maintenance contract to be awarded to local qualified stormwater management contractor

Design/Installation Information

  • Design: Steven Gruber (planning, Renewage LLC); David Whitney (PE, Eco Solutions); David Maciolek (PE, Aqua Nova); Evan Fitzgerald (MS environmental science)
  • Installation: Project management: Renewage LLC; Construction: SunUp Enterprises
  • Other project partners: Village of Wappingers Falls, Mayor Matt Alexander and staff; Village consulting PE Jay Paggi for prior studies and consulting; NYS Environmental Facilities Corporation for funding from the Green Innovative Grant Program
  • Date of installation: July-November 2013
  • Zoning change or special permit required: No. The site was not classified as a state wetland. The Village created a permanent easement agreement with the land owner.
  • Project cost: $725,000 (approximately $18/square foot)
  • Form of payment: $635,000 grant from NYS Environmental Facilities Corporation Green Innovation Grant Program, Village match 10% + balance

For Additional Site Information

Contact: Steven Gruber, Renewage LLC
Email: s@renewage.net
Phone: 631-605-1819