List of dam removals in the United States

This is a list of dams in the United States that have been removed as physical impediments to free-flowing rivers or streams. Dams are not included if they have instead failed, or if they have been decommissioned but not yet removed. Dam removal takes many forms, and some removals may leave structures behind or alter the natural course of a river.

According to the non-profit advocacy organization American Rivers, 2,119 dams were removed in the United States between 1912 and 2023. The peak year was 2018, which saw 109 removals. Pennsylvania removed 390 dams in this period, more than any other state. Mississippi is the only state with no documented dam removals.

Boardman River
The 46 ft Brown Bridge Dam, 56 ft Boardman Dam, and 34 ft Sabin Dam were removed from the Boardman River in Michigan as part of the Boardman River Dams Ecosystem Restoration Project after their hydropower was decommissioned in 2005.

Colorado River
Built in 1916, the 25 ft Fossil Creek Dam supported hydroelectric power production on Fossil Creek, a tributary of the Salt River via the Verde River. The dam was removed in 2008 to restore flow, travertine deposition, and native fish populations.

Columbia River
On the South Fork Clearwater River, the Grangeville Dam was a 56 ft, 440 ft arched concrete hydroelectric dam constructed by the Washington Water Power Company in 1911. A wooden fish ladder had been installed but it collapsed in 1949. The dam was removed in the interest of fish passage and since the hydropower facilities had become obsolete. The dam was destroyed by dynamite at 6:35 PM on August 19, 1963, following two prior detonations that day which had failed to collapse the structure. At the time, the dam was the largest ever to be removed, a record which stood for decades.

In 1971 the 39 ft tall Lewiston Dam was removed from the main stem of the Clearwater River just above its confluence with the Snake River. Built in 1927 as a hydroelectric facility, the dam lacked fish ladders and was rendered obsolete by the downstream Lower Granite Dam.

On the White Salmon River, the 123 ft Condit Dam blocked access for Pacific Salmon and steelhead runs on 33 mi of river. PacifiCorp proposed to remove the dam, rather than paying for fish passage upgrades. Removal was proposed in 2006, but actions from Skamania and Klickitat counties held up the process. In fall 2008, salmon were trucked up above to dam to allow them to spawn higher up the river. In October 2011, PacifiCorp contractors used explosives to blow a 15 ft hole in the dam to drain its reservoir and allow young salmon to enter the Columbia River and head to sea.

The 21 ft Milltown Dam lay the junction of the Clark Fork River and Blackfoot River in Montana. The dam held very high levels of toxic sediments from 100 years of mining and logging. Its 2008 removal improved water quality, trout habitat, and the general ecological condition of the watershed.

On the Sandy River in Oregon, the 50 ft tall Marmot Dam was removed by Portland General Electric in 2007. Its removal has been extremely successful at improving access for Pacific Salmon and steelhead to the upper Sandy River watershed up into the Mount Hood Wilderness.

Delaware River
The 6 ft tall Cuddebackville Dam on the Neversink River was built in two portions dating from the 1820s (for water diversion into a canal) and 1915 (for hydroelectric power). The dam had been abandoned since 1945, and was removed in October 2004 by the U.S. Army Corps of Engineers in a novel partnership with the Nature Conservancy. The removal benefited aquatic life in the area, specifically the Dwarf Wedge Mussel and the American Shad.

Elwha River
The largest dam removal project in history is the Elwha Ecosystem Restoration project on the Olympic Peninsula of Washington. Starting in 2012, and finishing in 2014, the 108 ft Elwha Dam and the 210 ft Glines Canyon Dam were removed to restore stocks of Pacific Salmon and trout species to the Elwha River watershed. The removal of these blockades allows migratory salmon to travel past the dam sites and upriver, an event that has not occurred since the dams' creation in 1913. After spawning there, the salmon die and their carcasses decompose, releasing marine nutrients laid down in their bodies as they fed in the open ocean. This reintroduction provides a valuable research opportunity for interested parties. Since the dam removal, reservoir beds that looked like moonscapes have returned to vibrant rich habitat. Within a year of the Elwha Dam removal, an increase in salmon-derived nutrients was documented in the American dipper.

Kennebec River
Built in 1837, the 24 ft tall Edwards Dam on the Kennebec River in Maine blocked passage to Atlantic Salmon and American Shad. Its 1999 removal was the result of a landmark case in which a U.S. federal agency, the Federal Energy Regulatory Commission, required the decommissioning and removal of a dam against the operator's wishes.

Klamath River
After more than 20 years of advocacy from the Un-Dam the Klamath movement, the first of the four dams on the Lower Klamath River are expected to be removed by November 2024. The first of these, the Copco Number 2 Dam, was removed in fall 2023.

Penobscot River
Two dams have been removed as part of the Penobscot River Restoration Project: the Great Works Dam in 2012 and the Veazie Dam in 2013, each 20 ft tall.

Rogue River
In 2008, the 80 ft tall Elk Creek Dam was removed from the Elk Creek tributary to the Rogue River.

Completed removals by dam height
This list includes all known removals of dams greater than or equal to 65 ft in height.