Saw Mill Creek Wetland Mitigation Bank | New York, US

Saw Mill Creek in New York has been threatened by illegal dumping and flooding for years. WSP was chosen to provide wetland design and restoration.


Location

  • New York, USA

Client

  • New York City Economic Development Corporation

Restoring New York City‘s first wetland mitigation bank

Saw Mill Creek, on the west shore of Staten Island, has been threatened by factors such as illegal dumping and invasive weeds for years. During Superstorm Sandy in 2012, the creek suffered from severe flooding, which only worsened the degradation. A strategy was needed to protect the 68-acre Saw Mill Creek wetlands, while also fostering sustainable waterfront development. These wetlands are located in an area with a mix of industrial land adjacent to salt marsh and coastal forests.

WSP was chosen by the NYC Economic Development Corporation, in collaboration with other city, state and federal agencies, to provide permitting and wetland restoration design for the Saw Mill Creek Marsh project, the city's first wetland mitigation bank. This pilot project, part of the Mitigation and Restoration Strategies for Habitat and Ecological Sustainability Initiative, sought to:

  • Improve water and sediment quality.
  • Increase plant and wildlife diversity.
  • Improve storm surge protection on the west shore of Staten Island and enhance its capacity to handle flooding.

WSP developed an ecological assessment methodology and conducted surveying and environmental testing, including sediment sampling and wetland functional assessments. A vegetation analysis and a threatened/endangered species analysis were also performed. WSP then provided a feasibility study, construction cost estimates, a construction schedule, and restoration design plans for emergent wetlands, scrub-shrub wetlands, freshwater forested wetlands, open water channels/pools, mudflat habitat, and uplands.

WSP is performing post-construction maintenance and monitoring of vegetation, biota and sediments to ensure the quality of habitat created and potential effect of exposure to wildlife for the restoration project in a highly urbanized area. The monitoring is being conducted in accordance with the Mitigation Banking Instrument, to establish guidelines and responsibilities for the establishment, use, operation and maintenance of the Saw Mill Creek Marsh.