On This Page
Issues and Challenges
- Dams in the U.S.
- The Owners’ Responsibility
- Why We Need Regulation and the Current State of Regulatory Programs in the United States
- The Increasing Hazard: Development Below Dams Increases the Risk
- Risk of Failure
- Making the Decision to Rehabilitate or Remove and How to Find the Funding
- Dueling Regulatory Requirements Can Significantly Slow Down the Rehabilitation Process
- Climate Change Is Affecting Dam Safety Management
- Emergency Preparedness is Critical But May Be Lacking in Some Locations
- Need for Improved Transparency and Communication with the Public
A Call to Action: What Can We Do To Improve Dam Safety?
- ASDSO
- U.S. Congress and the Administration
- National Dam Safety Program
- States and Federal Governments
- Dam Owners
- Emergency and Floodplain Managers
- Citizens
Issues and Challenges
Dams are a critical part of the nation’s infrastructure—equal in importance to bridges, roads, airports, and other civil works. Dams provide life-sustaining resources to people in all regions of the United States. They can serve several functions at once, including water supply for domestic, agricultural, industrial, and community use; flood control; recreation; and clean, renewable energy through hydropower. Despite their importance, our nation’s dams are aging and deteriorating while facing increased stress from a changing climate and increasing downstream populations that are potentially at risk. This situation demands greater attention and investment in measures that reduce risks to public safety and economic assets.
Dams in the U.S.
The 20th Century 
saw the most prolific building of dams in all regions of the United States. As more dams were constructed, dam failure became more common. Many dams failed due to a lack of proper engineering and maintenance, leading some to recognize that regulation may be needed. One of the earliest dam safety programs was enacted in California in the 1920s following the catastrophic failure of the St. Francis Dam, which resulted in more than 400 fatalities. Federal agencies, such as the USDA, Soil Conservation Service (now the Natural Resources Conservation Service), the U.S. Army Corps of Engineers and the Department of Interior, Bureau of Reclamation built many dams during the early part of the twentieth century and established construction and safety standards during this time. Slowly, more states began regulatory programs. It was not until the string of significant dam failures in the 1970s that awareness was raised to a new level among the states and the federal government that more needed to be done to protect life and property from dam failures.
Now, all states have a dam safety program, although there is a wide variation in size, budget, and enforcement capabilities.
The Owners’ Responsibility
A common misconception is that the U.S. Army Corps of Engineers owns or manages most dams in the country. In fact, dams are owned and operated by many different entities, with the majority of dams in the United States being privately owned. Private ownership makes dams a unique part of the national infrastructure compared to other facilities (roads, bridges, sewer systems, etc.) that are often owned by public entities.
Because of this, a dam could exist for many different reasons. Sometimes dams only serve the interest of the owner. For instance, a neighborhood association may own a dam so its homeowners have lakeside properties. A dam could serve the interest of the public. For instance, a locality may own a dam for water supply.
No matter a dam’s intended use, the owner is solely responsible for the safety and liability of the dam and for financing its upkeep, upgrade, and repair.
Why We Need Regulation and the Current State of Regulatory Programs in the United States
It is important 
that there is regulatory oversight to reduce the risk of dam failure or incidents. State agencies regulate the safety of most dams in the U.S. State dam safety programs have primary regulatory responsibility for over 70% of the nation’s dams. Dams owned by the federal government are typically self-governed by the federal agency that is responsible for the operation of the dam, such as the Army Corps of Engineers or the U.S. Bureau of Reclamation.
State dam safety programs oversee the classification, permitting, and inspection of dams, provide enforcement, oversee remediation of deficient dams, and work with local officials and dam owners on emergency preparedness.
Although most states have legislative authority to carry out a comprehensive dam safety program, many are lacking in specific areas. Some states are unable, by specific language in their law, to regulate certain types of dams, allowing these structures to fall between the regulatory cracks. Other states have limited ability to enforce the law. In some states, officials have no recourse if dam owners do not carry out safety repairs ordered by the state. Find Links to State Dam Safety Laws
While budgets for dam safety are increasing, there is still a need for more funding. In 2023, state budgets for dam safety ranged from $0 (Alabama) to $24 million (California), with the average annual state dam safety budget at about $1.57 million. Budgets for dam safety at the state level have increased in the last 10 years by about 60%.
The average number of regulated dams per state is about 1734, and the average number of dam inspectors per state is about 10. This means that each dam inspector is responsible for overseeing the safety of about 173 existing dams, plus the additional responsibilities of overseeing new dam construction.
The bottom line is that many state programs lack the necessary budgets, staff and authority to carry out these duties to ensure public safety. Although things have improved in the last 10 years, there is an ongoing, serious need in almost every state to provide more resources to these programs.
It is equally important to emphasize that the state of practice is advancing. The dam safety and engineering industry must adapt, as business as usual is not acceptable. Nationwide adoption of new advancements in inspection and assessments of dams is dependent on state programs’ adequate allocation of resources.
The Increasing Hazard: Development Below Dams Increases the Risk
Dams and the reservoirs they create are innately hazardous structures. Failure or mis-operation can result in the release of the reservoir contents—this includes water, mine waste, or agricultural refuse—causing negative impacts both upstream and downstream. or even at locations remote from the dam. Negative impacts of primary concern are the loss of human life and economic losses such as property damage, lifeline disruption, and environmental damage.
Additionally, the normal operation of a dam’s spillway, while designed to release excess water and maintain structural integrity, can also pose risks to nearby residents. Sudden or uncontrolled releases of water can lead to flooding downstream. These events can be particularly dangerous during periods of heavy rainfall or rapid snowmelt when the spillway must handle significant water volumes.
Some dams are considered
to have greater hazard potential than others. As of 2025, there are approximately 16,745 high-hazard potential dams in the United States. ‘High-hazard potential’ is a term used by most state dam safety programs and federal agencies as part of a three-tiered classification system used to determine how hazardous a dam's failure might be to the downstream area. It generally means if failure of the dam occurs, there will be loss of life.
It must be emphasized that hazard rating is not related to the condition of the dam or its associated structures, and the determination does not necessarily mean that these dams need repair. However, there are some high-hazard potential dams that are in need of repair.
High-hazard potential dams exist in every state and affect the lives of thousands downstream. The current issue and debate are over the increasing number of these high-hazard structures - not because more high-hazard dams are being built, but because more development is occurring downstream. Dam safety regulators generally have no control over local zoning laws or developers' property rights, and so this issue continues to worry regulators as the "hazard creep" trend persists.
Risk of Failure
Hundreds of dam failures have occurred throughout U.S. history, claiming thousands of lives, costing our economy millions of dollars, and resulting in environmental damage. Damage from a failure is not just limited to the dam itself and can result in the impairment of many other infrastructure systems, such as roads, bridges, and water systems. When a dam fails, resources must be devoted to the prevention and treatment of public health risks as well as the resulting structural consequences.
As the nation’s dams age and populations or industries grow downstream of dams, the potential for large-impact dam failures grows.
Although the majority of dams in the U.S. have responsible owners and are properly maintained, many dams still fail every year. From January 2010 to April 2020, states have reported 270 dam failures and 581 'incidents' - episodes where dams could have failed without intervention or if circumstances had not abated. Dam and downstream repair costs resulting from failures in 23 states reported in one recent year totaled $54.3 million.
Historically, dams that failed had some deficiency, which caused the failure. As of 2025, 2,522 of the nation’s 16,746 high-hazard potential dams are considered to be in poor or unsatisfactory condition, or about 15%. There are deficient dams in almost every state, and the risk of failure only increases as dams across the nation age.
Making the Decision to Rehabilitate or Remove and How to Find the Funding
With an increasing number of dams facing deteriorating conditions and heightened risks, stakeholders are confronted with a critical choice: should a dam be rehabilitated to meet modern safety standards, or is it more cost-effective and beneficial to remove it altogether? This complex evaluation process requires careful consideration of the dam’s original purpose, current condition, and the potential costs of repair versus removal. Additionally, ensuring the safety and longevity of the nation’s dams hinges on securing the necessary funding for these projects. Whether through rehabilitation or decommissioning, each decision impacts not only the safety of surrounding communities but also the long-term sustainability of infrastructure and resources.
Dams must be maintained to keep them safe. Over time, they require occasional upgrades or rehabilitation due to factors like deterioration, changing technical standards, improved techniques, a better understanding of the area's precipitation conditions, and changes in downstream populations or land use. When a dam's hazard classification is changed to reflect an increased hazard potential, the dam may need to be upgraded to meet an increased need for safety. Without the needed upgrades and rehabilitation, these dams cannot be expected to withstand more stringent flood and earthquake design values. For these reasons, thousands of dams remain in need of rehabilitation.
Before deciding on upgrades, however, it is crucial to evaluate whether the dam is still serving its intended purpose or if it should be removed. Some dams, particularly older ones, may no longer provide the benefits they were originally designed for. In such cases, removal or decommissioning could be a more cost-effective and environmentally beneficial option.
Advancing age can also make dams more susceptible to failure. While the age of a dam is not necessarily a direct indicator of its condition, age is indirectly an indicator revealing that many of the nation’s dams were not built to the standards of today. Some older dams are considered in poor condition for this reason alone, while others may have been inadequately maintained as well.
In a 2025 report, ASDSO estimated that the total cost to rehabilitate the nation’s non-federal dams is $165.2 billion. The cost to rehabilitate just the most critical dams was estimated at $37.4 billion, a cost that continues to rise as maintenance, repair, and rehabilitation are delayed.
Read ASDSO's Cost of Rehabilitating Dams in the U.S.
Lack of funding for dam upgrades is a serious national problem. Operation, maintenance, and rehabilitation of dams can range in cost from the low thousands to millions of dollars, and responsibility for these expenses lies with owners, many of whom cannot afford these costs. Some states offer loan and/or grant programs. There are three primary federal loan and grant programs that have been established in the last several years: The Watershed Rehabilitation Program (NRCS), the High-Hazard Potential Dam Rehabilitation Program (FEMA), and the Corps Water Infrastructure Financing Program (USACE). Funding from these programs will provide some relief and assistance to dam owners, yet the bulk of the funding costs still remain the responsibility of the owner.
In 2021, the American Society of Civil Engineers updated its Infrastructure Report Card. In this report, dams were given a 'D.’ This is mostly due to the number of deficient high-hazard dams and the lack of funding the sector currently receives.
Dueling Regulatory Requirements Can Significantly Slow Down the Rehabilitation Process
Dam rehabilitation delays result in putting the public at unnecessary risk.
Depending upon the type of work at a dam and its location, dam owners often need to secure permits from their state dam safety regulatory agency in addition to permits from state and federal environmental agencies. The environmental permitting process often trumps dam safety as dam owners need to comply with dam safety requirements and, at the same time, may be faced with large monetary fines if their water quality or downstream flow requirements are not met. Examples include dam owners who are reluctant to cycle critical valves as required by law due to the temporary release of turbid water or dam owners asking for temporary increases in storage levels of reservoirs to meet downstream flow requirements for environmental compliance even though the reservoirs have dam-safety-imposed reservoir restrictions.
Lowering of reservoirs for construction can also be troublesome for some dam owners who have sedimented reservoirs, as dewatering will result in the release of turbid water. Implications for construction include delayed work related to dam safety repairs, environmental mitigation costs that may significantly increase project costs, scope of work that may need to be modified, and repairs that may need to be completed underwater and may not be as robust as work performed under dry conditions.
Moderate to large dam rehabilitation projects can take years, if not a decade or more, to go from the initial planning to final permitting phases. It is not uncommon for large-scale projects to have delays related to the securing of environmental permitting or to have mitigation costs that are so significant that owners must either secure additional funding or change the design of the projects to a less robust alternative.
Climate Change is Affecting Dam Safety Management
A key challenge is understanding how climate change is affecting dam safety management. It is critical that the meteorological inputs used are accurate and reflect the characteristics of the given location. As climate changes, these inputs should be updated to reflect any changes that may affect the meteorological data used for design and rainfall-runoff evaluations.
Dams are designed to hold back and safely pass a specific amount of water. The amount of water is based on a dam’s hazard potential classification that is determined by the likelihood and severity of downstream consequences should the dam fail. Increasing precipitation and upstream flood events put stress on dams. Heavy precipitation and the resulting water flowing into a dam’s reservoir (flooding inflows) that exceed original design criteria are one of the most common reasons dams can be compromised and may lead to failure. Storm events affect other natural hazards that affect dam safety. For instance, mudslides that occur after severe wildfires may fill up reservoirs in unexpected ways.
In some locations, extreme rainfall events may be increasing either in the amount of rainfall or frequency or both, while in other locations these extreme events may be decreasing both in the amount or frequency. Regardless of how a changing climate affects a given location, the dam safety community should ensure that dams are safe against a wide range of potential outcomes and resilient against those changes.
With a changing climate, spillway activations and discharges may increase, necessitating more frequent spillway inspections after large storms, increased maintenance activities, and for some dams, implementation of necessary spillway upgrades, all of which are critical activities for a spillway’s safe continued use.
As the state of practice develops for incorporating the effect of climate change into dam safety (e.g., spillway evaluations), national standards for incorporating the new findings into methodologies and practices will be needed.
According to a report by the National Academies of Sciences, Engineering and Medicine, “While engineers continue to rely on PMP estimates when designing these large, critical facilities, the estimates themselves and the science behind them are based on outdated work. As climate change continues to supercharge storms, including rainfall amounts, that threaten existing infrastructure, there’s an urgent need to modernize PMP estimates and improve the science behind them.”
Read the National Academies Report
Emergency Preparedness is Critical But May Be Lacking in Some Locations
Emergency planning
and preparedness procedures must be in place in the event of a dam incident or failure. Until the last 10-plus years, a large percentage of dams in the U.S. did not have laws to require Emergency Action Plans (EAPs) or exercising procedures in place. EAPs play a big role in keeping people and property safe in the event of a dam breach or failure. Several states are making notable progress in increasing the percentage of dams with EAPs.
Emergency preparedness is improving, with the percentage of state-regulated high-hazard potential dams with an EAP increasing. The goal is for all high-hazard potential dams to have an EAP so that dam owners and local authorities are prepared for a sudden dam failure and the ensuing downstream consequence.
Up-to-date EAPs 
that are exercised and well understood by all stakeholders are vital to possibly prevent a dam failure or reduce the consequences of a dam failure. Still, EAPs should not take the place of keeping a dam well-maintained and up to current standards. Evacuations of densely populated areas can be difficult and costly as emergency managers must set up shelters and evacuate hospitals, nursing homes, jails, schools, etc. within the potential dam inundation zone. Evacuations can have significant psychological effects on people due to the disruption of daily life and the fear of the unknown.
Need for Improved Transparency and Communication with the Public
A critical issue that intersects with many of the challenges above is the inconsistency in public education about dams. The ordinary citizen is unaware that the beautiful lakes on which they boat, ski, or fish are only there because of manmade dams. Developers build within dam-break flood inundation areas knowing nothing about the potential devastation an upstream dam could cause should it ever fail. In fact, some developers and zoning officials are completely unaware of dams within their community. Even if citizens understand and are aware of dams, they still can be overly confident in the infallibility of these manmade structures. Living in dam-break flood-prone areas is a risk.
Dams can present significant risks not only to people living downstream but also to those engaging in water recreation. In recent years, more people have drowned near dams than have been killed in dam failures. Individuals who fish, swim, boat, or kayak near these structures often fail to recognize or fully understand the dangers involved. The areas around dams and spillways often have strong currents, submerged inlets, and dangerous hydraulic rollers that can trap and drown victims, even if they are wearing a life jacket. To mitigate these risks, more needs to be done to educate the public. Signage around dams needs to be improved and standardized, ensuring consistent warnings of the hazards. Low-head dams, in particular, are responsible for the highest number of drownings each year. Many of these dams are outdated, obsolete, and often abandoned—an issue that underscores the need for their removal to protect public safety.
Many dam owners are unaware of their responsibilities and liabilities towards public safety and the environment. Adequate understanding of proper dam maintenance and upgrade techniques is a typical problem among many owners across the United States.
Some groups put forth the message that dams are bad for the environment and advocate their removal. This may mislead the public into thinking that taking care of our dams is a worthless cause. In some cases, dam removal is the best solution when a dam no longer fulfills its purpose, but in all instances, the consequences should be considered before coming to this decision.
It is challenging to communicate complex or scientific information to a broad audience, but this issue must continuously be improved for the sake of public safety.
A Call to Action: What Can We Do To Improve Dam Safety?
ASDSO Shall:
✓ Support the improvement of state dam safety programs.
✓ Increase collaboration.
✓ Advance and expand the technical expertise of dam and levee safety practitioners through training and education programs.
✓ Reduce the potential for dam failure by promoting innovative approaches to fund dam rehabilitation.
✓ Reduce the consequences of dam failure by increasing public awareness, planning and preparedness.
✓ Advocate for laws, policies and government programs that serve to improve the safety of dams and reduce the risk to the public.
Read ASDSO's Strategic Plan 2022-2027
The U.S. Congress and the Administration Should:
✓ Recognize that public safety is a national responsibility.
✓ Support and fully fund the National Dam Safety Program and the CISA Dams Sector Specific Agency to increase national coordination and support for dam safety and security.
✓ Support and provide increased appropriations for all federal dam rehabilitation loan and grant programs including the High-Hazard Potential Dam Rehabilitation Program, the U.S. Army Corps of Engineers’ Water Infrastructure Financing Program, and the Watershed Rehabilitation Program.
✓ Review the implementation of the High-Hazard Potential Dam Rehabilitation Program, administered by FEMA, to assure that common sense, equitable and effective strategies are being used by FEMA to carry out the program.
✓ Provide adequate resources to all Federal agencies that own, regulate or provide technical or research support for dams.
✓ Continue to support directives established in the PRECIP Act of 2022, which directed NOAA to modernize probable maximum precipitation estimates to bring them more in line with the changing climate.
The National Dam Safety Program Should:
✓ Facilitate and support the strengthening of State dam safety programs.
✓ Maintain nationally accepted guidelines on dam safety program management, dam engineering and dam risk management technical topics. These national guidelines should be maintained and routinely updated by the FEMA, National Dam Safety Program.
✓ Effectively implement the National Rehabilitation of High Hazard Potential Dams grant program to cost-share safety upgrades to non-federal, high-hazard potential dams across all states.
✓ Implement a national public awareness campaign to educate individuals on the location and condition of dams in their area and become more “dam aware.”
✓ Establish a national investigation program, which would be activated after dam failures or incidents, to provide important lessons to be learned from those failures.
✓ Increase and improve training programs for dam safety engineers (including regulators, engineering consultants, owners, and operators).
✓ Promote a coordinated strategy within the dam safety community to study, archive and disseminate lessons to be learned from failures and incidents.
✓ Encourage better coordination between agencies (federal and state) by maintaining and enhancing national advisory boards.
States and Federal Governments Should:
✓ Maintain and constantly review and improve dam safety regulatory laws, policies and programs. Challenge all agencies to adopt the most current standards and practices.
✓ Provide sufficient resources, staffing and regulatory authorities to State and Federal dam safety programs.
✓ Ensure that adequate data on dams is available to policymakers to facilitate decision-making on funding, and to the general public to promote public awareness.
✓ Encourage better coordination between regulatory agencies (federal and state) regarding dams and shared regulatory responsibilities.
✓
Ensure that Federal agencies that own, operate, or regulate dams should meet the standards of Federal Guidelines for Dam Safety.
✓ Ensure that State agencies who regulate dams work toward meeting nationally accepted guidance detailed in the Model State Dam Safety Program Guidelines.
✓ Educate dam owners and encourage them to use experienced professional engineers.
✓ Implement innovative grant or loan programs to shore up deficient dams.
✓ Create State-administered low interest loan and grant programs for dam rehabilitation or fully fund the ones that States have on the books.
✓ Improve Downstream Hazard Classification (DHC) practices to ensure the safety of people downstream.
✓ Work with dam owners to develop emergency action plans for every high-hazard potential dam. Use a nationally accepted model/guide. Integrate exercising of these plans into the planning process.
✓ Encourage improved land use planning at the local level so that communication about how dams affect local areas is more accurately known and considered in future planning.
✓ Implement better public education about high-hazard potential dams, specifically ensuring the public has a better understanding of the dam condition rating system.
✓ Update hydrometeorological models and tools to account for what is known about climate change and current data.
✓ Develop a collaborative approach to integrate dam safety into environmental compliance permitting.
✓ Work toward better communications to reduce the consequences from failure. Share inundation maps and emergency response plans for high hazard potential and significant hazard potential dams among federal and state regulators, the emergency management community and the public as needed.
Dam Owners Should:
✓ Ensure dams meet current state, federal, and industry safety standards.
✓ Maintain and operate dams to assure that they do not fail. Work with state and local officials to mitigate the consequences of failures and incidents.
✓ Inform local officials of risks associated with dams.
✓ Develop emergency action plans (EAP) for every high-hazard potential dam. Use a nationally accepted model/guide. Integrate exercising into the planning process.
✓ Have a dam failure inundation map created as part of the EAP development process. Share plans and maps with local planners and first responders.
✓ Work with the state or federal regulator to comply with safety standards.
✓ Hire experienced professional engineers to oversee dam safety engineering issues.
✓ Improve signage, fencing and other barriers to educate and protect the public from drowning hazards around dams.
✓ Attend educational programs when offered by organizations and agencies.
Emergency and Floodplain Managers Should:
✓ Keep open lines of communication with State and Federal dam safety agencies to improve planning and preparedness for dam failures or incidents.
✓ Participate in educational programs to become more aware of dams and how they intersect with emergency and floodplain management.
✓ Encourage improved land use planning at the local level so that communication about how dams affect local areas is more accurately known and considered in future planning.
✓ Work collaboratively with dam safety managers to prepare for, respond to and recover from floods and dam safety incidents.
Citizens Should:
✓ Be aware
of their surroundings, risks they may face, and steps they can take now to protect themselves and their families from floods should a dam fail or release flood waters.
✓ Have a plan in place if an evacuation becomes necessary. Listen to first responders and emergency managers and follow directions given in the event of a dam incident or failure.
