Dam Removal on Wilton’s Comstock Brook Reopens and Restores River for Threatened Native Trout

Thousands of small dams dot the landscape across Connecticut on streams large and small, relics of an industrial past when water wheels provided critical power for mills and were retrofitted as private pleasure ponds before the Clean Water Act came into being.

Most lay hidden deep in the woods and out of sight, but many can be found in backyards and public parks where they have become popular water features.

Comstock Brook in Wilton runs parallel to Ridgefield Rd., from the town northern border to where it flows into the Norwalk River at Merwin Meadows Park. there are still at least 21 dams on this small stream where brook trout — the state’s only native trout — still live in the cold, deep pools and in pockets of rushing water behind boulders.

These dams, many of them no larger than a few feet high, are impenetrable barriers to brook trout and other aquatic creatures that need to move up the river to spawn or seek cold water during heat waves and droughts. Because they block fish passage, dams are one of the primary reasons — along with habitat loss and climate change — that native species like brook trout are losing out in the area’s rivers.

This summer, however, Trout Unlimited (TU) started working to reconnect Comstock Brook and restore critical habitat for the threatened native species in its waters by tearing out one of these dams just south of Nod Hill Rd.

“Most small streams in the area used to be teeming with Brook Trout and other native fish,” Conservation Chair of TU’s local Mianus Chapter Jeff Yates said. “The dozens of dams people built along Comstock Brook fragmented the trout habitat and accelerated their population decline. Unless we can reconnect the river by removing most of the dams, these brook trout won’t have a fighting chance to survive the warming waters, flash floods and other climate change impacts we are already seeing locally.”

After a period of focused planning, permitting, and preparation, it took only a few days in July to remove the dam, re-contour the stream and add new plantings. The landscape healed very quickly from the work.

Sam Gardner and Marci Sternheim own the property where TU completed the dam removal.

“For us, once we learned from Trout Unlimited how damaging a small dam like this is to the health of the river, taking it out was the only option. Our hope is that this project and our property can become an example to other dam owners on Comstock Brook and other local rivers of how you can take out a dam to benefit the fish and wildlife, but also end up with an equally beautiful and valuable view and water feature on your property,” they said.

After removing the dam, TU volunteers in partnership with the Norwalk River Watershed Association and the Pollinator Pathway sculpted the river into a more natural, sinuous flow and planted the new streambanks with more than 100 native trees and shrubs that will not only stabilize the stream and shade the river but also provide critical forage and habitat for all manner of wildlife, especially bees, butterflies and pollinating insects — all of which are in decline due to some of the same threats facing the brook trout.

With one project completed, TU is now turning its attention to the remaining small dams on Comstock Brook. Yates said the organization hopes to entice other dam owners to learn more about how they can work together to remove their dam but retain and even improve the property value and enjoyment of the river.

This fall, the group plans to host a gathering at the Sternheim-Gardner home to showcase the project, raise awareness of the need for dam removal and pollinator restoration, and encourage even more projects in the coming years.

Visit the Comstock Brook project’s website to learn more about Trout Unlimited and its work to restore Wilton’s native brook trout.