This project involved hydrologic and hydraulic evaluation of Bridge #3587 for the replacement of Route 2 over Boombridge Brook in Greenbush, Maine. The work was prepared for CLD as part of their preliminary design work for the Maine DOT on a replacement bridge.
The bridge is located just upstream of the confluence of Boombridge Brook with the Penobscot River. The bridge is subject to backwater flooding from the Penobscot River during high water events on the river. A large low swamp or wetland area upstream of the bridge serves as floodplain storage for floodwaters from the river. Flow at the bridge is influenced by runoff from the upstream watershed and backflow/return flow from the Penobscot River during high water.
Northstar evaluated backflow from the Penobscot River, upland flow and potential scour for existing and proposed bridge options to assist in selection of span length and foundation layout.