According to Ohio Laws and Rules, the owner of a dam is responsible for ensuring that the dam is maintained and operated in such a way that it does not constitute a hazard to life, health, or property. In other words, a dam owner is legally obligated to maintain the safe condition of the dam. Because a dam that holds back, or has the potential to hold back water, poses a foreseeable risk to persons and property downstream, the owner of the structure is responsible for taking precautionary measures.
These measures include periodic inspection, maintenance and monitoring, as well as needed repairs.
In addition, the Chief of the Division of Soil and Water Resources has the authority to require the owner of a dam to perform repairs, maintenance, or other remedial measures that the Chief has judged necessary to safeguard, life, health or property. Some of these repairs and remedial measures may require the services of a professional engineer to insure that they are done correctly.
The Dam Safety Engineering Program is happy to be of assistance to dam owners who have questions about the condition, or the safe operation of their dam. However, the owner is ultimately responsible for the condition of the dam and for maintaining its safe operating condition.
Importance of Dam Safety
More and more emphasis is being placed on emergency action plans as the public becomes more aware of the importance of dam safety. Since failure of a dam can take only hours or minutes, it is imperative to have a detailed plan of action ready for use. Dam owners and local officials must be prepared to act promptly and effectively when a dam begins to show signs of failure. Early identification of a hazardous situation may provide valuable additional time to warn and evacuate downstream residents and to implement measures to prevent or delay a dam failure.
Notable Dam Failures Nationwide
People refer to dam failures as disasters. By definition, a disaster is any event that causes great harm or damage, serious or sudden misfortune. Because of the rapid and unexpected manner in which dam failures can occur, they are classified in the same general magnitude as earthquakes and tornados. A few of the more notable dam failures are listed in the table below.
Causes of Dam Failures
Text and animations provided by the Association of State Dam Safety Officials.
Overtopping of a dam, as shown below, is often a precursor of dam failure. National statistics show that overtopping due to inadequate spillway design, debris blockage of spillways, or settlement of the dam crest account for approximately 34% of all U.S. dam failures.
Foundation Defects and Slope Instability
Foundation defects, including settlement and slope instability, cause about 30% of all dam failures.
Another 20% of U.S. dam failures have been caused by piping (internal erosion caused by seepage). Seepage often occurs around hydraulic structures, such as pipes and spillways; through animal burrows; around roots of woody vegetation; and through cracks in dams, dam appurtenances, and dam foundations.
|| Loss of Life
|| South Fork Dam
|| 2,209 dead
|| $17 Million
|| Buffalo Creek Dam
|| West Virginia
|| 125 dead
|| $400 Million
|| Canyon Lake Dam
|| South Dakota
|| 139 dead
|| $60 Million
|| Teton Dam
|| 11 dead
|| $400 Million
|| Taccoa Falls Dam
|| 39 dead
|| $30 Million
|| Lawn Lake Dam
|| 3 dead
|| $21 Million
There have been about 200 notable dam and reservoir failures in the world so far in the 20th century. More than 8,000 people have died in these disasters.
Failure of these dams as well as others has led in recent years to added emphasis on dams safety at the state and national levels. The potential for dam related disasters continues to grow with increasing residential and commercial development of lands downstream of dams. In many cases, existing dams will need to be modified to keep downstream areas safe. In other cases, dams will have to be removed.