Sheffield Brook, located in the densely developed shorefront known as Old Lyme Shores, routinely experiences flooding from both high precipitation events and coastal storm surges. By providing additional flood storage and conveyance, restoring wetland and floodplain areas, and installing tidal controls on the culvert(s) this project improves climate change resiliency.
Our work involved stream restoration to regrade the stream channel using bioengineering techniques and restoration of the floodplain in an approximately 1.1-acre parcel. Since the culverted section cannot be converted to an open channel, the existing culvert will be replaced with twin 36-inch culverts with tidal gates to prevent backflow during high tidal water. A HEC-RAS model was developed for the existing and proposed conditions. The private properties in this neighborhood will be positively impacted by the project with respect to lowering water surface elevations during flooding events.