Town of Cape Elizabeth
Total Cost of Project:
Culvert replacement tidal flow enhancement
The Town will replace two 36-inch wide by 48-inch tall metal corrugated culverts on Willow Brook with an approximately 11-foot wide concrete box culvert or open bottom culvert. The existing culverts are undersized and perched, creating a tidal restriction that limits tidal exchange upstream and downstream. The culverts also create a barrier to aquatic organism passage for most of the tidal cycle. The culverts provide 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 or open bottom culvert will improve 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 will enhance approximately 4 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 to be 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. Note, restoration work is planned for 2022 and this page will be updated upon work completion.