Obsolete Dams are a Hazard to People and Wildlife. We’re Working Together to Remove Them.

Sally Jewell, U.S. Secretary of the Interior

In the modern era, few things have inspired as much effort as humanity’s attempts to tame the world’s rivers. Across the world, from the Hoover Dam in Nevada to Egypt’s Aswan High Dam and China’s enormous Three Gorges Dam, these engineering feats have been viewed as symbols of progress and national pride for generations.

However, for every Hoover Dam that continues to provide benefits like water supply or clean energy, there are thousands of obsolete, abandoned and dangerous dams choking our waterways. In the United States alone, there are more than 87,000 dams recorded in the federal government’s inventory and as many as 2 million total dams, according to some estimates. Across the country, many of these dams no longer serve any useful purpose and thousands have been deemed as unsafe by dam safety experts. 

Secretary Jewell standing with a group of people next to construction equipment along the Musconetcong River.
Secretary Jewell at the Hughesville Dam Removal site. Photo by Tami Heilemann, Interior.

The cost of repairing and maintaining obsolete structures can be significant – often more expensive than dam removal itself – and the cost will only grow as our infrastructure continues to age. By 2030, up to 80 percent of our nation’s dams will be over 50 years old.

In addition to these growing costs and threats to public safety, we now understand that dams can harm our environment. Dams, culverts, irrigation diversion channels and other barriers restrict the ability of migratory fish species like salmon, steelhead, shad and many others to reach their historic spawning grounds. Native shellfish, amphibians, waterfowl and plants also depend on the ebb and flow of rivers, and dams and other barriers can impair and destroy these seasonal rhythms.  Dams can also choke spawning and rearing habitat with silt and debris, trap fertilizer and other contaminant run-off, leading to algae blooms and fish die-offs, and alter the ecology of rivers downstream. 

For all of these reasons, an increasing number of local communities, private dam owners, and local and state governments have come together over the past two decades to advance removal of obsolete dams. This trend complements ongoing efforts to mitigate the adverse effects of larger dams that provide very important societal benefits such as flood control, water supply, and hydropower production. Understanding how rivers react once these smaller, obsolete dams are removed will help further inform how measures such as fish passage and flow prescriptions at larger dams are developed and implemented to comprehensively address their ecological impacts while also maintaining their societal benefits.  

Last week, I joined with state officials and community partners to witness and celebrate the removal of the Hughesville Dam on the Musconetcong River in northern New Jersey, the fifth dam to be removed along this National Wild and Scenic River, reducing flood risk, improving habitat and augmenting recreational opportunities like fishing, boating and swimming. 

A lone rock in the middle of calm water flowing between the trees.
Musconetcong River - Hughesville Dam in Pohatcong, New Jersey. Photo by Katie Conrad, USFWS.

The Hughesville Dam removal is part of a larger partnership-driven effort to restore the river and its watershed, which over the past three centuries was dammed and diverted into the now-abandoned Morris Canal.

When completed, the Musconetcong River will join other successful river and estuary restorations across the nation. 

In the Pacific Northwest, for example, the U.S. Fish and Wildlife Service and National Park Service played a key role in the largest dam removal and ecosystem restoration project in history, when the Elwha Dam and Glines Canyon Dam on the Elwha River were removed. This has given endangered salmon, trout and other fish access to more than 70 river miles of their historic migration and spawning habitat. 

Further south in the Puget Sound, we worked with the Nisqually Indian Tribe, Ducks Unlimited and other partners to remove a dike and restore the Nisqually River Estuary – the largest tidal marsh restoration project in the region. Together, we have restored about 22 miles of the historic tidal slough systems and re-connected historic floodplains to Puget Sound, increasing potential salt marsh habitat in the southern reach of Puget Sound by over 50 percent. This restoration, much of which is encompassed by the Billy R. Frank, Jr. Nisqually National Wildlife Refuge, is providing an important boost to the recovery of Puget Sound salmon and other wildlife populations.

On the other side of the nation, one of our biggest collective successes has been the removal of the Great Works and Veazie dams on Maine’s Penobscot River. These obsolete dam removals marked the beginning of what has become the largest landscape-scale river restoration project in the country, culminating this summer with opening of the Howland Bypass. 

Pipe leading into the Musconetcong River to dredge up soil for restoration.
Hughesville Dam removal project in New Jersey. Photo by Katie Conrad, USFWS.

In total, this multi-year restoration effort has made more than 1,000 miles of native river habitat available for endangered Atlantic salmon and other aquatic species. It has also restored a vital cultural and natural resource for the Penobscot Indian Nation, whose identity is intertwined with the Penobscot River.

Over the past 20 years, the U.S. Fish and Wildlife Service has worked with 700 partners in local communities that have placed a value on free flowing rivers to remove more than 1,638 barriers to fish passage. These projects have reopened a total of nearly 24,000 river miles, and reconnected nearly 170,000 wetland acres – benefiting over 90 native fish species and hundreds other aquatic species, birds and mammals. In turn, these improvements have supported more than 219,000 jobs in the recreation and tourism industries, generating an estimated $11 billion in economic value to local communities.  These efforts join the many others that the Environmental Protection Agency, National Park Service, Bureau of Reclamation, Natural Resources Conservation Service and U.S. Army Corps of Engineers have supported across the country. 

But while we celebrate these successes, we know that there is much more to do.  We know that there are more local communities, private dam owners, and governments at the local and state level who are interested in removing dams that no longer provide public benefits, especially those that are cost-prohibitive to maintain or upgrade, pose significant public safety risks, and could provide significant ecological benefits if removed. Where that is the case, the federal government is prepared to do whatever it can to help. As recent successes illustrate, the measure of our progress isn’t always the size of the structures we build to control nature. It’s often manifested in those we remove – allowing nature to take its course.