Barely a mile from its headwaters, the Connecticut River is blocked by its first dam.
From its trickling start near the New Hampshire/Quebec border in Pittsburg to its enormous outflow at Long Island Sound, the Connecticut River is an emblem of New England’s human and natural environment.
Its beauty has inspired poets, novelists, photographers, painters among artists of all sorts. Its waters have sustained forests, estuaries, fish, Native Americans, Europeans and other life for thousands of years. Its flow has generated power for mills and electricity, helping to build hundreds of small towns and big cities.
While New England’s longest river is still a place of beauty, life and power, it is showing some signs of stress. Barely a mile from its inauspicious start at the outflow of Fourth Connecticut Lake, the Connecticut River is blocked by its first dam. Throughout its entire watershed – an area nearly the size of Maryland – more than 2,700 dams interrupt the basin’s natural flow.
These dams disrupt seasonal flows and movement of water, like spring freshets that nourish floodplain forests. They block fish that migrate to and from the sea, like salmon, shad, herring and eel.
Less conspicuous than dams are the 44,000 road-stream crossings in the watershed. Some of these culverts allow natural movement of water, fish and other organisms, while others block passage and fragment aquatic ecosystems.
Development and agriculture has taken a direct toll on river and stream habitat, floodplain forests, and other riparian natural communities
And while the waters of the Connecticut River and its tributaries have improved significantly since the 1972 passage of the Clean Water Act, the river still has pollution hotspots.
Turning Knowledge into Action
“Freshwater conservation has, to a large extent, been about undoing historical damage,” says Kim Lutz, director of the Conservancy’s Connecticut River Program. “We know much more today about what makes a river healthy. And we have to turn this knowledge into action.”
The Conservancy has been working in the Connecticut River landscape for more than 40 years. In fact, the river’s mainstem is bookended by Nature Conservancy preserves: Fourth Connecticut Lake in Pittsburg, N.H., and Griswold Point in Old Lyme, Conn. To date, the Conservancy has protected nearly 250,000 acres in the watershed.
In recent years, the Conservancy’s conservation planning efforts revealed the Connecticut River as an area of ecoregional significance and identified eight priority areas within the watershed. In New Hampshire, those priority areas include its North Country headwaters and the Ashuelot River.
And because of its ecological significance, the whole river is a conservation priority – one that requires conserving forests, rivers and lakes, and oceans and coasts. Among the strategies are to restore flow dynamics, protect floodplain forests, combat the spread of invasive species, among others.
Removing Obsolete Dams
One of the most obvious ways to re-connect the Connecticut is by removing old and obsolete dams throughout the watershed. In New Hampshire next summer, the Department of Environmental Services (DES) will oversee the removal of the old Homestead Woolen Mill Dam in Swanzey. The dam hasn’t powered the now-defunct mill in decades, is in disrepair, and the owner wants it removed.
This dam’s removal will re-establish an interconnected network of 346 miles of undammed river and tributaries, including 24 miles of re-connected and free flowing mainstem on the Ashuelot. People, fish, and natural communities will experience an Ashuelot that has not flowed this freely in more than 200 years!
Instream habitat will be improved not only for local and migratory fish, but also for the federally endangered dwarf wedge mussel, which has been found in this portion of the Ashuelot.
And talk about partners! This project is a great example of multiple partners focusing on a single conservation goal. The project is expected to cost about $395,000, and TNC is assisting by raising funds.
Restoring Healthy Flows
While dams can act as barriers to fish passage, they’re also essential to preventing flooding and generating electricity.
The U.S. Army Corps of Engineers owns and operates 14 flood control dams in the Connecticut River basin. Collectively those dams have an enormous influence on flow on the mainstem and its tributaries.
Now, the Army Corps and the Conservancy are working on an innovative project to restore healthy river flows. This Sustainable Rivers Project has identified the Connecticut River as one of a dozen U.S. rivers where the partners can conduct detailed assessments of flow. The Ashuelot River and the West River in Vermont are among the demonstration sites.
The ambitious study will give water managers a better understanding of the Connecticut River’s hydrology, and will enhance the Corps’ ability to manage its dams in ways that better protect people while also helping important ecosystems.
“The idea is to model the river so that we can understand where the water’s going and how it’s moving as a whole system,” says Christopher L. Hatfield, a study manager in the Corps’ New England district office.
Meanwhile, the Conservancy is conducting a companion study with the U.S. Forest Service to better understand one key ecosystem that depends on healthy flows: floodplain forests. This past summer and next summer, the Conservancy is looking closely at floodplain forests throughout the entire basin, including several in New Hampshire. Led by Conservancy scientist Christian Marks, the study is examining subtle changes in elevation and the tree species found there.
Among Marks’ early findings is that, minor adjustments to dams’ management might make a huge difference in restoring natural processes, thus improving chances for floodplain forests.
Because culverts can also disrupt stream systems, the Conservancy is working with state agencies and local communities to replace road-stream crossings with ones that reconnect miles of high-quality habitat.
One notable collaboration is in the Ashuelot River, where the Conservancy, volunteers, and the Ashuelot River Environmental Observatory have examined culverts and dams throughout the watershed. Now, the Conservancy and partners are preparing restoration plans and outreach to communities. Improvements to stream connectivity are a major goal of the Eastern Brook Trout Joint Venture, of which the Conservancy is a cooperator.
Cleaner and Healthier
Now far cleaner and healthier than they were only a generation ago, New Hampshire’s rivers are being rediscovered by cities and towns, bringing renewed economic and social vibrancy.
“Water management systems in the past were established with little understanding of the needs of rivers and streams,” says Lutz. “Today, we know that our rivers and streams must flow with enough water to sustain plants and animals, many of which are adapted to natural, seasonal changes. This means we can strive for a balance that meets our needs in the present while ensuring the health of our waters for the future.”