Fish passage and bridge replacement study
Northstar Hydro worked with Stantec to model and understand the flow of tidal and fresh water through the tide gates in the Route 1 causeway in Machias, Maine over the Middle River. Dynamic modeling of tide fluctuation was combined with numerous options for bridge replacement ranging from replace in kind to full restoration of tidal flow to the marsh upstream of the causeway. Project goals and challenges includes fish passage considerations, restrictions on tidal flow caused by current flap gated box culverts, storm surge overtopping of causeway, and deterioration of existing bridge.