New Culvert Design Restores Ecosystem
As part of the Coonamessett River Restoration Project, Tighe & Bond was responsible for designing a new 24-foot bridge to replace a series of three 24-inch diameter CMP culverts that prevented fish passage. The new bridge complements the recent dam removal downstream and conversion of cranberry bogs to a restored river. This new hydraulic system brought back an ecosystem that has been missing for approximately 300 years.
Tighe & Bond’s design included geotechnical evaluations, an alternatives analysis to evaluate various structure types, design drawings and specifications, and obtaining Chapter 85 approval through the Massachusetts Department of Transportation (MassDOT). Technical assistance was provided during the bid phase and construction administration services with periodic on-site observations performed.
The new bridge consists of a pre-cast concrete frame on pedestal spread footings. The design involved a roadway closure, stream bypassing, significant dewatering, and accommodated tidal salt water impacts. A sidewalk was constructed across the bridge in preparation for future recreational trail development along the river.
The structure provides a long-term durable bridge in compliance with MassDOT Chapter 85 requirements, stream crossing standards, and allows fish passage along a restored river.