River and wetland protection and dam removal can rapidly deliver benefits, such as supporting human health and conserving species and habitats, across watersheds and well beyond the banks of the protected waterways.
Americans are really good at building dams. Too good, in fact. Now, the
looming question is, can we get just as good at removing those dams that are
obsolete, hazardous to humans or ruinous to the environment and wildlife?
There’s growing evidence that we can—and must.
In July, the Biden administration released two reports on the feasibility of
removing four dams on the lower Snake River in the Columbia River basin. As
reported by The New York Times, 13 species of salmon and steelhead trout are
listed as threatened or endangered in the Columbia River basin, an area that
includes parts of Idaho, Oregon, Washington, Montana and British Columbia.
“The salmon are critical to the ecosystem of the river basin, serving as a
food source for animals as large as bears and as small as insects. They
contribute to the survival of endangered orcas, which depend on eating
Chinook in the winter and spring.”
Conducted by scientists at the National Oceanic and Atmospheric
Administration, the reports found that sweeping changes are needed to
restore salmon, in part by reintroducing ocean-going, river-spawning fish to
breeding grounds entirely blocked by the dams.
The Times report added that “Senator Patty Murray, Democrat of Washington,
who long resisted any salmon recovery plan that included removing the four
dams, joined Gov. Jay Inslee of Washington, a fellow Democrat, in
commissioning a separate study released this summer. That study found
removing the four dams was the most promising approach to salmon recovery.”
From grist mills to the Big Dam Era
There are more than 90,000 dams in the U.S. National Inventory of Dams
greater than head-height, and over 2 million smaller dams and stream
barriers throughout the country. About a third are used for recreation,
flood protection, irrigation or fire protection, and only a tiny fraction
for hydropower.
Despite all the hype about the awesome scale of some of the biggest
dams—Grand Coulee Dam on the Columbia River, for example, contains enough
concrete to build a highway from Seattle to Miami—dams overall generate just
7% of total U.S. electricity. Hydropower currently accounts for about 37% of
total U.S. renewable electricity generation. Given the explosive growth in
wind and solar, as well as the specter of prolonged drought forcing some of
the biggest power-producing dams—on Lake Powell and Lake Mead, to name
two—to potentially drop off the grid, that level is expected to decline
further, and soon.
On average, the age of dams across the U.S. exceeds 55 years; few dams have
been built in recent years because less than 2% of our rivers remain free
flowing. For wildlife and biodiversity, that’s a critical point: Although
freshwater makes up less than 3% of Earth’s water supply, the world’s
streams, creeks, rivers and lakes are home to almost half of all fish
species. In the U.S., river systems altered by dams and other barriers have
led to 40% of America’s fish species being listed as imperiled. As a result,
monitored populations of migratory freshwater fish have declined an average
of 76% between 1970 and 2016.
The first U.S. dams were constructed in the colonial period to aid
navigation, to provide power for grist mills and, over time, fuel the
fledgling textile and steel factories that made America a manufacturing
powerhouse. The Depression sparked the Big Dam Era, as the New Deal’s Public
Works Administration brought multiple large-scale dam projects to
realization. In the Pacific Northwest, the massive Grand Coulee Dam on the
Columbia River, constructed between 1933 and 1942, provided power for the
aluminum and aircraft factories that helped turn the tide in World War II.
The dam building boom continued into the postwar era. Chief among them was
the 710-foot-tall Glen Canyon dam across the Colorado River, built by the
U.S. Bureau of Reclamation from 1956 to 1966, which brought power and water
to the desert Southwest.
Problem is, these massive engineering projects drove the rapid growth to an
extent that is far above what the region can support, argues Giuliano Di
Baldassarre of the Department of Earth Sciences at Uppsala University,
Sweden, in a 2021 case study about the legacy of large dams in the U.S. As
dam development has plateaued, water wells are getting deeper and
groundwater levels are declining. Meanwhile, drought exposure has increased
because of population growth and agricultural expansion.
However, there is some good news. Efforts to take down outmoded dams and
restoring critical habitat are now paying off where U.S. dams first rose—on
the rivers along New England’s historic mill towns.
The removal of the Edwards Dam on the Kennebec River in Maine, in 1999,
marked the first time the federal government determined the public benefits
of a free-flowing river were greater than those provided by an existing dam.
Built in 1837, the dam proved disastrous for local stocks of species like
American shad, Atlantic and short-nosed sturgeon, Atlantic salmon, striped
bass, American eel and river herring, once found in great abundance in tidal
rivers up and down the Atlantic Seaboard.
In the past 25 years, some 1,800 dams have come down across the U.S, reports
the nonprofit group American Rivers. Most are in the Northeast, though the
movement is spreading. For example, in 2020, 69 dams were removed in 23
states, with Ohio leading the way with 11 and Massachusetts and New York
with 6 dam removals each.
When the dam breaks
Where the political will exists, dam breaching can’t come some enough. Under
threat from development, pollution and climate-change impacts, the health of
the nation’s lakes, rivers, and wetlands are declining at a much faster rate
than terrestrial ecosystems. The dire state of U.S. freshwater resources has
prompted The Pew Charitable Trusts to engage with NatureServe and Michigan
State University to build national databases of watershed conditions and
barriers that alter the natural flow of rivers, streams, and other
freshwater bodies.
“River and wetland protection and dam removal can rapidly deliver benefits,
such as supporting human health and conserving species and habitats, across
watersheds and well beyond the banks of the protected waterway,” writes
Nicole Cordan, who oversees river protection and restoration work for The
Pew Charitable Trusts. “We hope these interactive database maps will add to
the growing understanding of the nation’s vital waterways and result in
science-based actions that will ensure their restoration and conservation
for generations to come.”
Check out the databases to see if an old dam impeding a river or stream in
your area is a candidate for removal and then join your neighbors in the
fight to restore free-flowing waters. True progress requires recognizing
when you’ve made a mistake and then committing to undo it.
Let’s face it: We are now forced to reverse any number of so-called
advancements once hailed as proof of American ingenuity. Cars powered by
internal combustion engines (and fueled by leaded gasoline) are giving way
to electric vehicles; fire-retardant asbestos, known to have deadly health
effects since the early 1900s, is finally being mitigated; synthetic
pesticides, from the DDT of Rachel Carson’s day to today’s insidious
neonicotinoids, are slowly being replaced by organic treatments and
integrated pest management.
And one by one, those damnable dams are being breached. Good riddance!