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.[1]
Completed removals by watershed
Boardman River
The 46-foot (14 m)[2] Brown Bridge Dam, 56-foot (17 m)[3] Boardman Dam, and 34-foot (10 m)[4] 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-foot (7.6 m)[5] 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.[6]
Columbia River
On the South Fork Clearwater River, the Grangeville Dam was a 56-foot-tall (17 m), 440-foot-long (130 m) 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.[7] At the time, the dam was the largest ever to be removed, a record which stood for decades.[8]
In 1971 the 39 ft (12 m) 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 (37 m) Condit Dam blocked access for Pacific Salmon and steelhead runs on 33 miles (53 km) 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-foot (4.6 m) hole in the dam to drain its reservoir and allow young salmon to enter the Columbia River and head to sea.
The 21-foot (6.4 m) 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.[9]
On the Sandy River in Oregon, the 50-foot (15 m) 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-foot (1.8 m) 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-foot (33 m) Elwha Dam and the 210-foot (64 m) 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.[10] 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.[11]
Kennebec River
Built in 1837, the 24-foot (7.3 m) 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.[12] The first of these, the Copco Number 2 Dam, was removed in fall 2023.[13]
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 feet (6.1 m) tall.[14]
Rogue River
In 2008, the 80-foot (24 m) 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 feet (20 m) in height.
Planned and proposed removals
| Dam | Height | Expected year | Location | Watercourse | Watershed |
|---|---|---|---|---|---|
| Copco Number 1 Dam | 132 ft (40 m) | 2024 | Siskiyou County, CA 41°58′48″N 122°20′04″W / 41.98°N 122.3344°W |
Klamath River | Klamath River |
| Iron Gate Dam | 173 ft (53 m) | Siskiyou County, CA 41°56′02″N 122°26′07″W / 41.9339°N 122.4353°W | |||
| John C. Boyle Dam | 68 ft (21 m) | Klamath County, OR 42°07′25″N 122°02′53″W / 42.1235°N 122.048°W | |||
| Matilija Dam | 198 ft (60 m) | Ojai, CA 34°29′N 119°19′W / 34.49°N 119.31°W |
Matilija Creek | Ventura River | |
| Rindge Dam | 100 ft (30 m) | 2025–2035 | Malibu Creek State Park, CA 34°03′53″N 118°41′56″W / 34.0646°N 118.699°W |
Malibu Creek | Santa Monica Bay |
| Dam | Height | Location | Watercourse | Watershed |
|---|---|---|---|---|
| Glen Canyon Dam | 710 ft (220 m) | Coconino County, AZ 36°56′15″N 111°29′04″W / 36.9375°N 111.4844°W |
Colorado River | Colorado River |
| O'Shaughnessy Dam | 430 ft (130 m) | Yosemite National Park, CA 37°56′51″N 119°47′18″W / 37.9475°N 119.7883°W |
Tuolumne River | San Joaquin River |
| Ice Harbor Dam | 213 ft (65 m) | Franklin County and Walla Walla County, WA 46°14′59″N 118°52′48″W / 46.2496°N 118.88°W |
Snake River | Columbia River |
| Lower Monumental Dam | 152 ft (46 m) | Franklin County and Walla Walla County, WA 46°33′45″N 118°32′13″W / 46.5624°N 118.537°W | ||
| Little Goose Dam | 253 ft (77 m) | Columbia County and Whitman County, WA 46°35′15″N 118°01′34″W / 46.5875°N 118.0261°W | ||
| Lower Granite Dam | 181 ft (55 m) | Garfield County and Whitman County, WA 46°39′38″N 117°25′42″W / 46.6605°N 117.4283°W |
By state or territory
Alabama
California
Connecticut
Delaware
Florida
Georgia
Idaho
Louisiana
Maine
Maryland
Massachusetts
New Hampshire
New Jersey
New York
North Carolina
North Dakota
Ohio
| Dam | Dam height | Watercourse | Removal completed | Notes |
|---|---|---|---|---|
| Pinery Feeder Dam | Cuyahoga River | 2020 | [15] | |
| Brecksville Dam | 8 ft (2.4 m) |
Oregon
| Dam | Dam height | Watercourse | Removal completed | Notes |
|---|---|---|---|---|
| Marie Dorian Dam | 8 ft (2.4 m) | Walla Walla River | 1997 | The dam blocked passage to Pacific Salmon and steelhead into the Blue Mountains from the Columbia Basin. |
Rhode Island
South Carolina
Tennessee
Vermont
Virginia
West Virginia
Washington, D.C.
Wisconsin
Completed removals
| Dam | Watercourse | Removal completed | Notes |
|---|---|---|---|
| Island Woolen Mill Dam | Baraboo River | 1972 | Opened 120 miles (190 km) of a Wisconsin River tributary to fish and wildlife.[16] |
| Reedsburg Woolen Mills Dam | 1973 | ||
| Wonewoc Dam | 1996 | ||
| Waterworks Dam | 1998 | ||
| Oak Street Dam | 2000 | ||
| LaValle Dam | 2001 | ||
| Linen Mill Dam | 2001 |
Planned removals
| Dam | River | Removal timeframe | Notes |
|---|---|---|---|
| Junction Falls Dam | Kinnickinnic River | 2023–2040 | In 2018, River Falls, Wisconsin, approved the removal of two little-used dams in the city. This would return the Kinnickinnic River to a free-flowing state and restore the city's namesake falls.[17] |
| Powell Dam | 2025–2040 |
Wyoming
References
- ^ "Saying Adios to 80 Dams in 2023 —". www.americanrivers.org. American Rivers. 13 February 2024. Retrieved 20 February 2024.
- ^ "Brown Bridge Dam Failure Report". michigan.gov. Michigan Department of Environment, Great Lakes, and Energy. June 2014. Retrieved 17 January 2023.
- ^ "Boardman Dam in Grand Traverse County, MI". The Record. April 7, 2021. Retrieved 17 January 2023.
- ^ "Sabin Dam in Grand Traverse County, MI". The Record. April 7, 2021. Retrieved 17 January 2023.
- ^ Springer, Abe; Ledbetter, Jeri. "Fossil Creek". azheritagewaters.nau.edu. Arizona Heritage Waters. Retrieved 17 January 2023.
- ^ Marks, Jane C.; Haden, George A.; O’Neill, Matthew; Pace, Cinnamon (November 2010). "Effects of Flow Restoration and Exotic Species Removal on Recovery of Native Fish: Lessons from a Dam Decommissioning". Restoration Ecology. 18 (6): 934–943. Bibcode:2010ResEc..18..934M. doi:10.1111/j.1526-100X.2009.00574.x. S2CID 21724032.
- ^ Winter, Brian D. (April 1990). "A Brief Review of Dam Removal Efforts in Washington, Oregon, Idaho and California" (PDF). National Oceanic and Atmospheric Administration. Retrieved 8 September 2023.
- ^ McCully, Patrick (1996). "Getting Old: Dam Aging and Decommissioning". International Rivers. Zed Books. Retrieved 8 September 2023.
- ^ "Milltown Dam & Reservoir". missoulacounty.us. Missoula County, MT. Retrieved 17 January 2023.
- ^ "Salmon Populations". Archived from the original on 2009-01-07. Retrieved 2008-11-03.
- ^ Crane, Misti (December 28, 2015). "River ecosystems show 'incredible' initial recovery after dam removal". phys.org. Retrieved December 28, 2015.
- ^ Flaccus, Gillian (26 February 2022). "Major hurdle cleared in plan to demolish 4 Klamath River dams". opb. Retrieved 16 January 2023.
- ^ "Work on Copco No. 2 Dam Removal Comes to a Close". Klamath River Renewal. 2 November 2023. Retrieved 20 November 2023.
- ^ "Penobscot River Restoration Project". 25 September 2013. Retrieved 3 May 2020.
- ^ "Dam Removal". Cuyahoga Valley National Park. National Park Service. December 14, 2022. Retrieved 17 January 2023.
- ^ "Running Free, The Baraboo River Restoration Story" (PDF). Retrieved 2021-12-19.
- ^ Seitz, Grey (4 November 2022). "Federal funds could quicken Kinnickinnic River dam removal". stcroix360.com. Retrieved 16 January 2023.
External links
Media related to Removed dams in the United States at Wikimedia Commons
