A new kind of culvert is being installed on an Ausable River tributary in Wilmington. The project is part of a initiative led by the Ausable River Association (AsRA) and the Adirondack Chapter of The Nature Conservancy (the Conservancy) to improve stream connectivity, fish habitat, and community flood resilience in the Ausable watershed by replacing road-stream crossings with designs engineered to allow for natural stream pattern and flow.
Under rural roads throughout the Ausable watershed, streams are routed through plastic or steel pipes often significantly narrower than the width of the streams at normal flow. During high flow events, undersized culverts can become blocked by debris and sediment, flooding roads and property. High flows forced through undersized pipes scour away soil at the downstream ends of culverts, creating large drop-offs impassable to fish and other erosion and sedimentation problems.
The new culvert, designed by North Woods Engineering of Saranac Lake, uses an open-bottom aluminum arch wide enough to span the natural streambanks and low enough to avoid raising the level of the road. “What you end up with is a healthy restored stream with a lid on it,” Kelley Tucker of AsRA said in a statement sent to the press about the project. “It’s designed to allow 100- year flood flows to pass through with room to spare. Because the stream underneath is intact, sediment and debris move through efficiently, reducing flood risks and reducing maintenance costs to the town.”
The Town of Wilmington Highway Department is building the culvert with assistance from the Town of Jay Department of Public Works. The US Fish & Wildlife Service, AsRA, and the Essex County Soil and Water Conservation District are providing oversight and technical assistance.
The Conservancy’s work to assess and prioritize road-stream crossings in the watershed, which began in 2010, combines ecological data with information from town officials about culverts with frequent flooding or maintenance problems.
The Conservancy secured grant funding for this project from the Wildlife Conservation Society’s Climate Adaptation Fund. AsRA is coordinating the project and has provided additional funding through the New York State Department of State under Title 11 of the Environmental Protection Fund.