Letting Rivers Run: 3 Ways We Work with Dams

Dams have driven immense progress around the world, but many pose serious threats to our rivers.

Environmental Flows

Learn how river management along the Susquehanna and Potomac Rivers affects water quality and wildlife.


Penobscot River

Watch a video from the river's edge and learn more about restoration of the Penobscot River.


Story Highlights
  • Dams have driven immense progress around the world, but many pose serious threats to our rivers.
  • The Nature Conservancy has developed 3 creative solutions to restore the health of rivers below dams while also meeting he needs of people.
  • Learn how the Conservancy is applying these tactics on the Connecticut, Susquehanna and Penobscot Rivers.
"With a little creativity and a lot of determination, we're finding it possible to balance the many gifts our rivers provide."

Kate Dempsey, senior policy advisor for the Conservancy in Maine

By Kate Frazer and Madeline Breen

Standing inside a large dam with thousands of gallons of water tumbling around you, it’s hard not to be impressed by its power. But while dams have driven immense progress, many have also depleted fish populations, degraded water quality and diminished centuries-old cultural traditions.

Removing dams is a proven way to rejuvenate fisheries and revive the natural services our rivers provide. But not all dams are created equal. In fact, some dams come with their own sets of benefits — like water supply, flood control and clean, renewable energy.

Is it possible to balance the services our rivers provide when they are harnessed with the services they provide when they’re allowed to run free?

With thousands of new hydropower operations planned around the planet, The Nature Conservancy is racing to answer this question. Visit three East Coast rivers where we’re helping to implement solutions that could shape the future of freshwater management around the world.

Solution 1: Help Fish Get to the Other Side
Connecticut River 

Inside Holyoke Dam, two scientists sit at a large window, counting the fish swimming past in the murky green water. After traveling more than 80 miles up the Connecticut River, fish like shad and salmon encounter a state-of-the-art fish passage — similar to a detour on a highway. After finding one of two fish elevators, they’re nudged into a "crowding area," hoisted up a steel tower and funneled through a 300-foot-long flume over the dam and into the river.

But most of the 2,700 dams in the Connecticut River watershed are much smaller than the Holyoke and lack fancy fish elevators. The collective impact of these blockages is enormous. Kim Lutz, director of the Conservancy’s Connecticut River program, is leading an effort to unclog the watershed by removing the barriers that present the greatest impediments to fish on key tributaries like the Westfield River in Massachusetts and the Eightmile River in Connecticut.

When removal isn’t possible, fish ladders and other bypass devices can make dams more fish-friendly. “We shouldn’t have to choose between healthy fisheries and the other services our rivers provide,” says Lutz. “By reopening some of these passageways, we can maintain critical links in the food chain while still using water to meet our needs.”

Solution 2: Go with the Flow
Susquehanna River 

Opening up pathways for migratory fish can restore living links between the sea, bays, rivers and estuaries. But no river can thrive without another key element: a healthy pulse of flowing water.

The Susquehanna River, which courses through rural and urban areas of Pennsylvania, New York and Maryland on its way to the Chesapeake Bay, has one of the heaviest concentrations of electricity-generating facilities in the world. And the pressures do not end there. Every year, more of the river’s water is diverted for agriculture, drinking water, mining and even golf courses. When a river’s natural flow is disrupted, complex lifecycles — from fish spawning and migration to plant growth — begin to unravel.

“We’re facing the reality that consumptive water use in the Susquehanna basin could increase by 50 percent by 2025,” says Michele DePhilip, the Conservancy’s director of freshwater conservation in Pennsylvania. “But we’ve learned a great deal about how to withdraw, store and release water while meeting nature’s needs.”

Working with the Susquehanna River Basin Commission and the U.S. Army Corps of Engineers, the Conservancy is now using that knowledge to recommend changes to the way the Conowingo Dam and other dams on the river are managed. The key, says DePhilip, will be to mirror the river’s natural rhythms as closely as possible.

Solution 3: Save the Whole River
Penobscot River 

Of course, deciding what to do about dams in a particular watershed isn’t all about fish passage and river flow. “The fact is, the more you can look at the whole system, the better the outcome will be,” says Kate Dempsey, senior policy advisor for the Conservancy in Maine. “To truly save a river, you have to work with everybody.”

Nowhere has that been more apparent than on the Penobscot River in northern Maine.

When discussions about restoring the Penobscot began, stakeholders brought many different perspectives to the table. But in the end, an unlikely group of partners — one power company, one Native American tribe, six environmental groups and numerous state and federal agencies and riverside communities — designed a plan that would work for the whole community.

The plan? Two dams closest to the ocean will be removed and a state-of-the-art fish bypass will be installed at a third dam further upstream, restoring more than 1,000 miles of river habitat. Meanwhile, energy production will be increased at other dams, providing the ability to maintain current hydropower levels.

“At the end of the day, restoration isn’t just about river miles, it’s about a huge group of people coming together to make a resource work for many,” says Dempsey. “With a little creativity and a lot of determination, we’re finding it possible to balance the many gifts our rivers provide. And that’s a good thing, because we can’t afford to lose any of them.”


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