Going with the natural flow
Work to reverse centuries of man-made changes to Red Brook nears completion
WAREHAM - Where the salt water of Buttermilk Bay meets the cold water springs that feed Red Brook, sea-run trout find the right conditions to lay their eggs, burying them under the stream-bed’s gravel to hide them from predators.
But man-made alterations of Red Brook, a 5-mile cold water stream that divides Wareham and Plymouth, have made survival hard for the trout. Over the centuries, the stream was dammed with dirt structures and concrete dikes to provide power for mills and to direct water to the cranberry bogs when needed for harvest. The needs of the fish and the ecosystem that supported them along with a range of native species took a back seat.
At a time when the state’s fisheries are under stress from development and climate change, a public-private partnership of state agencies, environmentalists, and other volunteers is finishing a three-year effort to return Red Brook, one of the few coastal cold water streams remaining in Massachusetts, to its natural condition.
The removal of a series of concrete flumes - U-shaped dams with cut-out centers to allow wooden boards to “gate’’ or regulate the flow of water - liberates the current to run freely and scour natural channels. The result will be good for the stream’s ecosystem, good for the fish, and good for the people who like to catch them, project participants said.
“The fishing and the environment go together. You improve the environment, and the fishing improves,’’ said John Kokoszka, of the Southeastern Massachusetts chapter of Trout Unlimited, one of the volunteers recently at the site where an old bridge altering the channel near Head of the Bay Road was removed in August.
An excavator worked with state environmental staff and volunteers to widen Red Brook’s west channel, restoring what ecologists believe was the river’s path before the bridge and dams altered it. The bridge will be replaced by a lighter footbridge for hikers in the Red Brook Preserve. The stream restoration project also includes new native-species plantings to shade the fast-moving but shallow stream and help keep water temperatures down.
“Removing the dams gives the brook resiliency to climate change,’’ said Tim Purinton, acting director of the state’s Division of Ecological Restoration. Restoring Red Brook’s natural flow combats the predicted increases in global temperatures that threaten cold water streams, he said. And sound wetlands help safeguard against a worrisome effect of global warming - increased flooding. Natural stream beds and surrounding uplands absorb flood waters from heavy downpours.
Purinton said the work at Red Brook is a signature effort in the state’s attempt to restore coastal and inland water habitats at a time when fish such as river herring are in decline. Along with fish, American eels, amphibians, invertebrates, birds, and plants also benefit from healthy wetlands.
A few feet away from the restored flow near Head of the Bay Road, a newly formed shallow pool about 6 feet across will provide habitat for frogs and dragonflies, said Steve Hurley, the state’s Southeast District fisheries manager.
Working with local river advocacy groups, the state Department of Fish and Game’s Riverways Program has undertaken stream restoration projects all over the state, focusing on factors that most impact river health.
Completed stream restoration projects included the removal of 19th-century dams along Plymouth’s Town Brook, habitat restoration in the Neponset River in Milton and Boston, and dam removal on the winding Housatonic River in the Berkshires. Among the program’s current priorities are cold-water habitat restoration on Plymouth’s Eel River, aquatic habitat restoration of the Mill River in Taunton, and dam removal on the Jones River in Kingston.
At Red Brook, staff and volunteers recently examined the fruits of the past two summers’ efforts. Upstream at New Way Dam, workers had removed hundreds of yards of fill along with a concrete dam, restoring the original ground level and planting native wetland species such as bayberry, red maples, Joe Pye weed, boneset, and sedges. Significantly, too, water temperatures were measurably colder.
Farther upstream, where a dam had been removed two years ago, aquatic plants bloomed in the water along with native grasses, and the project had the look of completion, said Nick Wildman, the Red Brook project manager for the Riverways Program.
“Fish come here to spawn. It’s beautiful,’’ he said. The project is a success “if it looks like we were never here.’’
The restoration work has already been tested by a tropical storm in August that dumped 6 inches of water on Red Brook Preserve without damage to the brook, said Hurley.
He pointed to the upended tree roots the project had left at points in the stream bed to give fish places to hide. A current scouring a channel around fallen branches is a natural stream feature, he said.
State officials praised the contributions of a dozen partners in the project, including the Trustees of Reservations, the land preservation organization that was given the Red Brook Preserve eight years ago by its owner, the Lyman family, with the idea of preserving it for the benefit of trout and other species.
Trout Unlimited has a special interest in the brook, too, officials said. All parties agreed that trout fishing in Red Brook will be done on a “catch and release’’ basis.
Back at the site of the recently removed bridge near Head of the Bay Road, Hurley made another discovery.
The tiny frog pool created by the restoration effort was already a success: A frog had moved in, and a dragonfly circled above.
Robert Knox can be reached at email@example.com.