Vol. 4, No. 3
More dams razed, many more to go (cont'd)
New dam removal programs
In the last two centuries, thousands of dams were constructed along rivers and streams in the Gulf of Maine region for a variety of purposes including hydropower, irrigation and flood control. Like those in Maine, many are well past their prime, unproductive and unsafe. The U.S. Fish and Wildlife Service estimates that in New England, 90 percent of former stream habitats are blocked to migratory fish. While there are no comparable figures for rivers in the Canadian Gulf of Maine, a 1999 Environment Canada report, Environmental Impact of Barriers on Rivers Entering the Bay of Fundy, stated that few of the rivers flowing into the Bay have adequate fishways around dams or other barriers. Of the 44 large to medium sized rivers flowing into the Bay, researchers found that 57 percent have dams or causeways that impede river flow and cause significant ecological impact.
From the northern reaches of the Gulf to areas of greater population density in the south, the number of dams increase substantially. In Massachusetts, the Department of Environmental Management oversees 3,000 dams in the state, most constructed before 1900 for water supply, saw mills, power supply and recreation. About 350 of these dams are on the state "high hazard" list, meaning if they failed they could cause loss of life and property. About 800 are rated as "significant hazard," meaning they could potentially cause the same destruction if they burst.
Following on the heels of the Edwards Dam demolition, the Massachusetts Executive Office of Environmental Affairs, led by Secretary Bob Durand, launched an interagency dam removal program last year called River Restore. Karen Pelto, who coordinates the program, says many of the state's dams are 50 years of age and older, while the average life span for a dam is 50 years. She says the most damaged dams and the ones causing the most harm to fish species will go first.
"We are only looking at dams that don't make sense," she says, adding that the team has visited 30 sites and have narrowed the list to four that might become projects next year. The Old Berkshire Dam in the western part of the state was removed this fall.
The Billington Street Dam on Town Brook in Plymouth is the state's first coastal dam being considered for removal. Constructed in the late 1790s as a foundation for the Holms and Packard Anchor Forge mill, the dam is among five on Town Brook blocking fish passage. Once a prolific alewife stream for Plymouth's earlier settlers, today the fish are caught by specialists from the Massachusetts Division of Marine Fisheries and transported to their spawning grounds in the back of a tanked truck.
Pelto says inspecting the older dams often uncovers clues to their ecological and human history. At the Billington Street Dam, for example, inspectors used a hand auger to drill into a small impoundment behind the earthen structure and found the original streambed of Town Brook lies up to two feet (0.6 meters) below a layer of sand and silt. Small cobbles from the original dam are also buried under the sediment.
Financing and assistance for the project is being provided by several state and Federal agencies including Massachusetts Office of Coastal Zone Management, the U.S. Environmental Protection Agency, the Department of Environmental Management, and the Town of Plymouth, which owns the site. Deconstruction of the Billington Street Dam is scheduled for next year, Pelto says.
Earlier this year New Hampshire established a coalition of government agencies and conservation groups called the River Restoration Task Force, which is cataloging the state's dams and identifying those that are obsolete and should be removed to improve habitat for fish and other wildlife. Scott Decker, a fish habitat biologist from the New Hampshire Fish and Game Department and a member of the task force, says of the 4,800 dam sites previously documented by the state, "We're looking at a 1,000 that are designated inactive and serve no useful purpose." Of those, he says, 12 have the potential for removal in the next few years.
The state hopes to remove three dams from the Ashuelot River watershed in the next couple of years. The Homestead Dam in West Swanzey, the Winchester Dam in Winchester, and the McGoldrick Dam in Hinsdale are among some 50 that block the Ashuelot watershed. Removing the Homestead Dam alone would open up about 30 miles (48 kilometers) of river, Decker says.