Marmot Dam on the Sandy River, after its removal in 2007. Photo by Thomas O’Keefe, American Whitewater.
Let’s collectively celebrate the good news for rivers in 2023 – not only did the decommissioning of four dams on the Klamath River commence, but also 79 dams were removed across the US opening up 1,160 upstream river miles (American Rivers Database of Dam Removals 1912-2023). In the last seven years, 587 dams have been removed, reconnecting 7,098 upstream river miles. The pace and scale of dam removal is increasing, and it has proven to be one of the most environmentally efficient and cost-effective ways of restoring rivers, bringing wide-ranging benefits to both people and ecosystems.
In this issue of Free Flow, we highlight the successful watershed restoration efforts of dam removals that have been completed to date and look forward to all the good work that is still critically needed.
Legacy Dams
Starting in earnest in the mid-1850s dams were placed in the northeast and Midwest, to support lumber mills and material transport. In the West, damming waterways was seen as a mighty accomplishment to tame the wild and allow for settlements, agriculture and progress. The era of large-scale hydroelectric dam building spanned roughly four decades, from the 1930s through the 1960s. These dams have all aged significantly, and the landscape and populations have evolved; many stand forgotten and unseen, and function in diminishing capacity. The cost of needed repairs is often greater than the value the aged infrastructure may (or may not) provide. What they all are doing is impacting the entire river corridor both up and downstream, and that impact has continued over the decades of the lifespan of these dams.
Dam Problems
It is common knowledge that dams block upstream and downstream passage for adult and juvenile fish. Multimillion-dollar infrastructure improvements – such as fish ladders, fish transfer stations and improved spillways – have helped to improve these conditions, but they are nowhere near adequate to support a resurgence of thriving fisheries. Dams have directly contributed to the extinction of 29% of the salmon populations in California and the Pacific Northwest, and the threat or endangerment of many that remain, according to American Rivers. River hydrology and water quality are also clearly impacted by dams.
Dams are engineered to retain water and alter hydrology; that is their job and they do it very well. They are equally effective at retaining sediment, the solid materials that are moved by and along rivers. Typically, sediment is contributed to a river throughout its course, but mostly in its upper reaches. That sediment bounces, rolls and is flushed downstream and over years, decades, centuries and millennia the processes of hydrology (precipitation and streamflow) combined with erosion and sedimentation of the river corridor, has created the form of the waterways as we experience them today. Removing sediment from the equilibrium, as dams do, disrupts river function both physically and biologically (across huge areas – especially if dams are located in the mid- and upper reaches of watersheds). For example, massive bank erosion occurs as ‘sediment-starved’ rivers eat away at banks, and scour of the riverbed occurs causing widespread incision, undermining roads and bridges and streamside infrastructure. Sediment is not only sand and rocks, but other materials with important nutrients for the whole system. Lack of distribution of sediment is a huge problem for society – costing hundreds of millions of dollars a year in damages.
In this issue of Free Flow, we highlight the successful watershed restoration efforts of dam removals that have been completed to date and look forward to all the good work that is still critically needed.
Legacy Dams
Starting in earnest in the mid-1850s dams were placed in the northeast and Midwest, to support lumber mills and material transport. In the West, damming waterways was seen as a mighty accomplishment to tame the wild and allow for settlements, agriculture and progress. The era of large-scale hydroelectric dam building spanned roughly four decades, from the 1930s through the 1960s. These dams have all aged significantly, and the landscape and populations have evolved; many stand forgotten and unseen, and function in diminishing capacity. The cost of needed repairs is often greater than the value the aged infrastructure may (or may not) provide. What they all are doing is impacting the entire river corridor both up and downstream, and that impact has continued over the decades of the lifespan of these dams.
Dam Problems
It is common knowledge that dams block upstream and downstream passage for adult and juvenile fish. Multimillion-dollar infrastructure improvements – such as fish ladders, fish transfer stations and improved spillways – have helped to improve these conditions, but they are nowhere near adequate to support a resurgence of thriving fisheries. Dams have directly contributed to the extinction of 29% of the salmon populations in California and the Pacific Northwest, and the threat or endangerment of many that remain, according to American Rivers. River hydrology and water quality are also clearly impacted by dams.
Dams are engineered to retain water and alter hydrology; that is their job and they do it very well. They are equally effective at retaining sediment, the solid materials that are moved by and along rivers. Typically, sediment is contributed to a river throughout its course, but mostly in its upper reaches. That sediment bounces, rolls and is flushed downstream and over years, decades, centuries and millennia the processes of hydrology (precipitation and streamflow) combined with erosion and sedimentation of the river corridor, has created the form of the waterways as we experience them today. Removing sediment from the equilibrium, as dams do, disrupts river function both physically and biologically (across huge areas – especially if dams are located in the mid- and upper reaches of watersheds). For example, massive bank erosion occurs as ‘sediment-starved’ rivers eat away at banks, and scour of the riverbed occurs causing widespread incision, undermining roads and bridges and streamside infrastructure. Sediment is not only sand and rocks, but other materials with important nutrients for the whole system. Lack of distribution of sediment is a huge problem for society – costing hundreds of millions of dollars a year in damages.
Anonymous activist artists painted a “cut here” scissor graphic on the obsolete 200-foot tall Matilija Dam near Ojai, California in 2011. The dam is planned for removal in 2030. Photo courtesy of American Rivers.
|
More than 530,000 dams block rivers across our country (SARP 2024). Of the 92,075 dams large enough to be included in the National Inventory of Dams (greater than 6-ft tall), only 19% provide flood risk reduction, 18% provide irrigation or water supply, and 3% provide hydropower (USACOE 2024). 85% are 50 years or older and 63% are privately owned. Many no longer provide the services they were built to provide decades to centuries ago. Notably, there are 133 retired hydropower projects where dam infrastructure remains in the river (Johnson et al. 2020). There are also an astonishing 440,000 smaller, lowhead dams that are not in the National Inventory that are even more prone to being obsolete and unmaintained.
Removing the aging infrastructure, where feasible, allows the watershed to heal itself. And thanks to decades of activism,we are starting to see the acceptance of dam removal as a way to evolve our energy infrastructure and provide huge benefits to our anemic river systems. |
Fights for Freeing Rivers Begin
Activism for dam removal heated up in earnest in the 1980’s when Earth First! activists unfurled a banner down the face of the Glen Canyon Dam. The graphic made it look like the dam had developed a 300-ft crack down the middle. The Edwards Dam removal on Maine’s Kennebec River in 1999 was a turning point in discussions about dam removal. It was the first time the Federal Energy Regulatory Commission (FERC) ordered a dam removed because its costs outweighed its benefits. This signaled a shift in thinking from a radical concept to what can be a proven tool for restoration. And it has had a ripple effect.
The dam removal movement has been gaining momentum. Many dams have reached the end of their useful lives and pose public safety risks, negatively impact fish and other aquatic life, and can be costly liabilities to their owners. Countless dams are abandoned, not profitable, or require expensive repairs and upgrades. Removing dams restores native aquatic life to rivers, increases climate resilience, and reduces the risk of aging dams failing and causing catastrophic flood damages and even loss of human life.
Addressing Concerns about Dam Removal
Decisions to remove aging dam infrastructure are often clouded by uncertainties over potential environmental benefits and detriments of removal. Concerns and uncertainties surround sediment release especially (e.g., Downs et al. 2009). In a detailed assessment of completed dam removals, the USGS found that in many cases more than a third, and sometimes two-thirds, of stored sediment has been evacuated within weeks to months of dam removal (Major, J.J. 2017, USGS DRIP Database), and relatively stable channels within former reservoir beds have established themselves swiftly. Major downstream channel adjustments achieved apparent stability within months to years. Despite concerns, most removals to date have shown adverse geomorphic impacts are short-lived and have been neither as damaging nor as long-lasting as feared.
Activism for dam removal heated up in earnest in the 1980’s when Earth First! activists unfurled a banner down the face of the Glen Canyon Dam. The graphic made it look like the dam had developed a 300-ft crack down the middle. The Edwards Dam removal on Maine’s Kennebec River in 1999 was a turning point in discussions about dam removal. It was the first time the Federal Energy Regulatory Commission (FERC) ordered a dam removed because its costs outweighed its benefits. This signaled a shift in thinking from a radical concept to what can be a proven tool for restoration. And it has had a ripple effect.
The dam removal movement has been gaining momentum. Many dams have reached the end of their useful lives and pose public safety risks, negatively impact fish and other aquatic life, and can be costly liabilities to their owners. Countless dams are abandoned, not profitable, or require expensive repairs and upgrades. Removing dams restores native aquatic life to rivers, increases climate resilience, and reduces the risk of aging dams failing and causing catastrophic flood damages and even loss of human life.
Addressing Concerns about Dam Removal
Decisions to remove aging dam infrastructure are often clouded by uncertainties over potential environmental benefits and detriments of removal. Concerns and uncertainties surround sediment release especially (e.g., Downs et al. 2009). In a detailed assessment of completed dam removals, the USGS found that in many cases more than a third, and sometimes two-thirds, of stored sediment has been evacuated within weeks to months of dam removal (Major, J.J. 2017, USGS DRIP Database), and relatively stable channels within former reservoir beds have established themselves swiftly. Major downstream channel adjustments achieved apparent stability within months to years. Despite concerns, most removals to date have shown adverse geomorphic impacts are short-lived and have been neither as damaging nor as long-lasting as feared.
|
The time between removal and recovery of a river is very short while the positive impact on people and nature is far-reaching. And we have no time to waste. 29% of Pacific Northwest and California salmon populations are now extinct and one-third of those remaining are listed as threatened or endangered under the Endangered Species Act (American Rivers Summary 2023 Dam Removals).
Pacific Rivers currently has an Endangered Species Act petition for Washington coast spring Chinook underway with the National Marine Fisheries Service. Other organizations have brought forth additional petitions for more fish in more areas. One study by the Center for Biological Diversity compared the actual recovery rate of 110 ESA-listed species with the projected recovery rate in their federal recovery plans, finding 90% of species recovering as specified by the plans. We know this measure is effective at bringing additional protections to recover salmon – for which the first step is undoubtedly river recovery. |
Jane Stackhouse with the Oregon League of Conservation Voters Metro Climate Action Team joins activists calling for dam removal during a vigil for salmon in Vancouver, WA.
Photo by Alex Milan Tracy. |
Money Talks
Removing aging dams can be significantly cheaper than rehabilitating them, according to a study from the Division of Ecological Restoration (IEC 2015). Over 30 years, removal of the three dams in the study was 60% less expensive, on average, than repairing and maintaining them. Though more expensive in the short term, removal eliminates the expenses associated with insurance coverage, maintenance and safety repairs, as well as direct and indirect expenses associated with fish and wildlife protection (e.g., fish ladders and mitigation for fish mortality). In addition, removal often generates income from newly available recreation opportunities – including fishing, kayaking, and rafting – which may result in a net economic benefit to river communities.
Removing aging dams can be significantly cheaper than rehabilitating them, according to a study from the Division of Ecological Restoration (IEC 2015). Over 30 years, removal of the three dams in the study was 60% less expensive, on average, than repairing and maintaining them. Though more expensive in the short term, removal eliminates the expenses associated with insurance coverage, maintenance and safety repairs, as well as direct and indirect expenses associated with fish and wildlife protection (e.g., fish ladders and mitigation for fish mortality). In addition, removal often generates income from newly available recreation opportunities – including fishing, kayaking, and rafting – which may result in a net economic benefit to river communities.
Dam failure on Michigan's Tittabawassee River: After three days of rain, the Edenville Dam collapsed in May 2020, releasing a torrent that overtopped the downstream Sanford Dam and flooded the city of Midland, located about 128 miles northwest of Detroit. Thousands of people were temporarily evacuated and 150 homes were destroyed. U.S. Air National Guard
Photo by Master Sgt. Scott Thompson. |
Dams require ongoing maintenance. When older dams are no longer used for their original purpose, dam owners may defer maintenance to the point where the dams pose a threat to public safety (see Dam failure on Michigan's Tittabawassee River in 2020). The elimination of ongoing maintenance with the dam itself, but also the associated re-supply of sediment in the river downstream of the dam can result in long-term savings. A study by Portland State University researchers found that billions of dollars could be saved if the nation's aging dams are removed rather than repaired (Zbiniew et al. 2018). Many dams are still important and serve a purpose, and only a small percentage will be removed in the next decade, but cost savings can still be realized even with individual dam removals.Many older hydroelectric dams were built to support nearby mills, factories and communities, and have relatively small generating capacity. As the U.S. power grid has shifted to more regional rather than local production, power produced by smaller dams can be more expensive than power from regional sources or may no longer be needed. A pertinent example is the Lower Snake River Dams. They produce the most electricity in months when it is needed least (when the region actually has a massive surplus), and the least in the late summer months when it is needed most. It simply is not the right solution for energy production going forward (NW Energy Coalition 2024).
Neighboring communities benefit from free-flowing rivers with increased whitewater recreation and other river-related tourism when visitors spend money with local guides, outfitters, restaurants, and other businesses, bringing new money to oftentimes remote communities. |
The enhanced recreational opportunities help to pivot from any reliance on reservoirs (Brower and Sheremet 2017). Many whitewater parks are being constructed at small dam removal sites, and the excitement about the opportunity to float new and longer stretches of a river draws in many new river users.
And, while not an immediate injection of funds, we must not undervalue the ecosystem services, such as water quality improvements and habitat provisions, that dam removal can provide. While these are often not directly monetized or readily witnessed by the community, they absolutely contribute to the well-being of communities, culture and place.
Who Pays for Dams?
It is rare for a private owner of a dam to foot the entire bill for removal. There are grant programs in place to help with the costs, and dam removals can be sponsored by other entities. Landowners are often absolved of financial responsibility.
THE GOOD NEWS is the current administration secured passage of the bipartisan Infrastructure Investment and Jobs Act, which includes $2.4 billion for the removal, retrofit and rehabilitation of dams, and of that, over $800 million is made available for dam removal. Two years since the bill passed, 89 dam removals have been funded (U.S. Fish and Wildlife Service, Fish Passage Portal).
And, while not an immediate injection of funds, we must not undervalue the ecosystem services, such as water quality improvements and habitat provisions, that dam removal can provide. While these are often not directly monetized or readily witnessed by the community, they absolutely contribute to the well-being of communities, culture and place.
Who Pays for Dams?
It is rare for a private owner of a dam to foot the entire bill for removal. There are grant programs in place to help with the costs, and dam removals can be sponsored by other entities. Landowners are often absolved of financial responsibility.
THE GOOD NEWS is the current administration secured passage of the bipartisan Infrastructure Investment and Jobs Act, which includes $2.4 billion for the removal, retrofit and rehabilitation of dams, and of that, over $800 million is made available for dam removal. Two years since the bill passed, 89 dam removals have been funded (U.S. Fish and Wildlife Service, Fish Passage Portal).
|
Let ‘em Go!
There are tens of thousands of outdated, obsolete dams nationwide whose impacts outweigh the benefits they provide. Most no longer serve their original purpose, are not being maintained, and pose safety hazards. Our nation is facing multiple interconnected crises, from climate change, to injustice, to the loss of nature and biodiversity. Rivers flow through these challenges, and dam removal is a powerful solution that is proven and works on the watershed scale. |
Vigil for Salmon protest. Photo by Ben Herndon.
|
REFERENCES:
American Rivers Database of Dam Removals 1912-2023: www.americanrivers.org/DamRemovalDatabase
Peter W. Downs, Yantao Cui, John K. Wooster, Scott R. Dusterhoff, Derek B. Booth, William E. Dietrich & Roy Brouwer, Oleg Sheremet, The economic value of river restoration, Water Resources and Economics, Volume 17, 2017, Pages 1-8, ISSN 2212-4284, https://doi.org/10.1016/j.wre.2017.02.005.
IEC 2015.“Economic and Community Benefits From Stream Barrier Removal Projects in Massachusetts.” PREPARED BY Industrial Economics, Incorporated. PREPARED FOR: Massachusetts Department of Fish and Game, Division of Ecological Restoration.
Johnson M.M., S.-C. Kao, N.M. Samu, and Uría-Martinez, R., (2020). U.S. Hydropower Retired Facilities, 2020. HydroSource. Oak Ridge National Laboratory, Oak Ridge, TN.
Major, Jon J. (2017). Geomorphic responses to dam removal in the United States—a two-decade perspective.
Northwest Energy Coalition 2022 report "Smart Planning Will Drive Replacing the Power From the Lower Snake River Dams”
Leonard S. Sklar (2009) Managing reservoir sediment release in dam removal projects: An approach informed by physical and numerical modeling of non‐cohesive sediment, International Journal of River Basin Management, 7:4, 433-452, DOI: 10.1080/15715124.2009.9635401
Southeast Aquatic Resources Partnership, National Aquatic Barrier Inventory and Prioritization Tool 2024, www.aquaticbarriers.org
U.S. Army Corps of Engineers, National Inventory of dams, https://nid.sec.usace.army.mil/#/
U.S. Geological Survey Dam Removal Information Portal. https://www.usgs.gov/tools/usgs-dam-removal-information-portal-drip
Zbigniew J. Grabowski, Heejun Chang, Elise L. Granek. Fracturing dams, fractured data: Empirical trends and characteristics of existing and removed dams in the United States. River Research and Applications, 2018
American Rivers Database of Dam Removals 1912-2023: www.americanrivers.org/DamRemovalDatabase
Peter W. Downs, Yantao Cui, John K. Wooster, Scott R. Dusterhoff, Derek B. Booth, William E. Dietrich & Roy Brouwer, Oleg Sheremet, The economic value of river restoration, Water Resources and Economics, Volume 17, 2017, Pages 1-8, ISSN 2212-4284, https://doi.org/10.1016/j.wre.2017.02.005.
IEC 2015.“Economic and Community Benefits From Stream Barrier Removal Projects in Massachusetts.” PREPARED BY Industrial Economics, Incorporated. PREPARED FOR: Massachusetts Department of Fish and Game, Division of Ecological Restoration.
Johnson M.M., S.-C. Kao, N.M. Samu, and Uría-Martinez, R., (2020). U.S. Hydropower Retired Facilities, 2020. HydroSource. Oak Ridge National Laboratory, Oak Ridge, TN.
Major, Jon J. (2017). Geomorphic responses to dam removal in the United States—a two-decade perspective.
Northwest Energy Coalition 2022 report "Smart Planning Will Drive Replacing the Power From the Lower Snake River Dams”
Leonard S. Sklar (2009) Managing reservoir sediment release in dam removal projects: An approach informed by physical and numerical modeling of non‐cohesive sediment, International Journal of River Basin Management, 7:4, 433-452, DOI: 10.1080/15715124.2009.9635401
Southeast Aquatic Resources Partnership, National Aquatic Barrier Inventory and Prioritization Tool 2024, www.aquaticbarriers.org
U.S. Army Corps of Engineers, National Inventory of dams, https://nid.sec.usace.army.mil/#/
U.S. Geological Survey Dam Removal Information Portal. https://www.usgs.gov/tools/usgs-dam-removal-information-portal-drip
Zbigniew J. Grabowski, Heejun Chang, Elise L. Granek. Fracturing dams, fractured data: Empirical trends and characteristics of existing and removed dams in the United States. River Research and Applications, 2018
