Connecticut College-backed plan would restore Mamacoke Brook; commission finds no significant adverse impact

Acting Chairman Tali Maidelis presided as the Waterford Conservation Commission on Feb. 26 heard a presentation on a proposed restoration of Mamacoke Brook at 435 Mohegan Avenue Parkway. Josh Wilson, a professional wetlands scientist with BioHabitats, presented the plan on behalf of Connecticut College and described a three-segment approach to repair severe erosion and restore natural channel function.

Wilson said the project treats the channel as an intermittent watercourse that has been degraded by runoff from Route 32. The restoration would involve about 0.7 acres of wetland and watercourse impact while restoring approximately 0.75 acres. The upper segment would use Post-Assisted Log Structures (PALS) — large, staked woody debris installed by hand or with small all-terrain vehicles to slow flows. The middle section calls for a series of boulder cascades, riffles and armored plunge pools formed with natural boulders roughly 2 feet in diameter, and addition of material to raise the eroded bed to reduce downcutting. The lower segment includes a marsh area and stands of phragmites; the plan calls for above-ground herbicidal treatment of phragmites where needed and installation of linear waddles to spread waters across the marsh without excavation.

Wilson told the commission the work is intended to slow flow velocities, improve infiltration and allow channel migration in a more natural pattern. He said no heavy construction equipment will be used in the upper section and that material access there will be by hand or small all-terrain vehicles. BioHabitats and Green Vest were cited as firms with prior similar project experience in the mid-Atlantic; funding has been provided by the National Fish and Wildlife Foundation. Wilson also said the project requires permits from the U.S. Army Corps of Engineers and State of Connecticut authorities, would take at least two construction seasons and is expected to be monitored for about five years.

Commissioners asked questions during the presentation. The project team said a public information meeting conducted by the Connecticut College Arboretum drew roughly 20–25 attendees and received generally positive feedback. After discussion, Commissioner David Lersch moved and Commissioner Wade Thomas seconded a motion to find that the Mamacoke Brook Restoration project does not pose any significant adverse impact; the vote was 5–0.

Next steps identified in the meeting record include permit applications to the Army Corps and the State and continued coordination with college staff and contractors. The commission did not record any conditions or mitigation beyond the plan as presented.