Dam Safety

Commemorating National Dam Safety Awareness Day in the U.S. on May 31

Commemorating National Dam Safety Awareness Day in the U.S. on May 31

May 31 is the annual commemoration of National Dam Safety Awareness Day in the U.S., established to remember the failure of South Fork Dam in Johnstown, Pa., on May 31, 1889.

The Johnstown disaster was the worst dam failure in the history of the U.S., with over 2,200 lives lost, according to the Association of State Dam Safety Officials. More recent dam safety incidents, such as the leak at Panguitch Lake Dam in Utah, remind us of the importance of properly maintained and operating dams.

Dams provide a life-sustaining resource but are innately hazardous structures. Failure or misoperation can result in the release of the reservoir contents, causing negative impacts upstream or downstream or at locations remote from the dam. Dam failures have caused loss of human life, economic loss including property damage, lifeline disruption and environmental damage. Without proper maintenance, routine inspection, necessary upgrades and coordinated emergency planning, the risks become greater. It is of the utmost importance that those living near dams know their risks. Communication helps increase knowledge, understanding and awareness of dams and the risks dams pose.

National Dam Safety Awareness Day was created to encourage and promote individual and community responsibility and best practices for dam safety, and what steps people can take to either prevent future catastrophic dam failures or lessen the impact if a failure was to occur, ASDSO said. Another important goal of National Dam Safety Awareness Day is to promote the benefits that dams offer.

There are more than 90,000 dams in the National Inventory of Dams, and thousands of the most critical high-hazard potential (HHP) dams in the U.S. do not meet current safety standards. As of 2021, there are about 16,500 HHP dams in the U.S., defined by the majority of state dam safety regulatory programs and federal agencies as a dam in which failure or misoperation will probably cause a loss of human life. The American Society of Civil Engineers (ASCE) gave the nation’s dams a grade of D in its 2021 Infrastructure Report Card. This report is issued every four years.

State dam safety programs oversee classification, permitting and inspection of dams; provide enforcement; oversee remediation of deficient dams; and work with local officials and dam owners on emergency preparedness. 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.

In a 2023 report, ASDSO estimated that the cost to rehabilitate the nation’s non-federal dams is $157.5 billion. The cost to rehabilitate just the most critical dams was estimated at $34.1 billion, a cost that continues to rise as maintenance, repair and rehabilitation are delayed. Many dam owners, especially private dam owners, find it difficult to finance rehabilitation projects.

ASDSO offers an Awareness Center on its website that provides information on dam safety, including a roadmap to reducing dam safety risks and information on legislative advocacy.