Willow Brook Culvert Replacement

In 2022, the Town replaced two 36-inch wide by 48-inch tall metal corrugated culverts on Willow Brook with an 11-foot wide concrete box culvert. The pre-existing culverts were undersized and perched, creating a tidal restriction that limited tidal exchange upstream and downstream. The culverts also created a barrier to aquatic organism passage for most of the tidal cycle. The crossing provides structural support to two large diameter sewer lines, located directly above the culverts, for which Portland Water District owns an easement through the Project area. The new concrete box culvert improves hydraulic performance and aquatic connectivity. A tidal study conducted by the Town concluded that an 11-foot wide culvert is adequately designed for tidal conditions for 60-80 years under a high or intermediate-high sea level rise scenario. The Project enhanced approximately 2 acres of freshwater and estuarine wetland and approximately 2,000 linear feet of stream channel by improving hydrologic connectivity and aquatic organism passage. The culverts that were replaced are located on land conserved by Cape Elizabeth Land Trust. The Town will maintain the new culvert for the long-term maintenance of hydrologic connectivity.