The Friends of the Winooski River (FWR) successfully replaced an undersized culvert located on Hayes Road in the Town of Duxbury. The project is in the Crossett Brook subwatershed, a tributary of the Mad River.
The original crossing washed out during a storm event in May 2011. Due to confusion at the time, the adjacent landowner replaced the structure with a poorly built, undersized culvert. A 35-foot long metal tank culvert conveyed Crossett Brook under the roadway. The capacity of this structure was far less than what was needed based on bankfull channel widths and information about the stream’s hydraulic geometry. The shape of the culvert was distorted with sagging and buckling of the roof under the roadway. The tank had rusted and was in poor structural condition. A large amount of fill existed over the culvert that was held in place by concrete blocks and large boulders. Some of the blocks appeared to be unstable and erosion was taking place between and around the blocks.
If the culvert had failed, FWR’s consulting engineer on the project estimated that 700 cubic yards of dirt and sediment material would be washed into the stream. Debris and water build up behind the culvert could cause considerable downstream scour.
The FWR project replaced this undersized and likely-to-fail structure with an open bottom arch that meets current State standards for fish passage and hydraulic capacity. Milone and MacBroom was the consulting engineer and Griffin and Griffin was the contractor. Work began in early September and was completed in early October.
Vermont Watershed Grant funds, dollars arising when motorists purchase a Vermont Conservation License Plate for their automobiles, were combined with multiple other sources of funds to install the new replacement structure. To learn more about the Conservation License Plate and the Vermont Watershed Grants Program, go to this web site: