Current through Register Vol. 48, No. 07, July 26, 2024
Section 72-2 - Dam Classifications and ExemptionsA. General. All dams and reservoirs subject to this regulation shall be classified according to their size and hazard potential. Classifications shall be made in accordance with this section and are subject to final approval by the Department. It may be necessary to reclassify dams as additional information becomes available.B. Size Classification. The classification for size based on the height of the dam and storage capacity shall be in accordance with the table below. Size classification may be determined by either storage or height, whichever gives the larger size capacity.Category | Impoundment Storage (Acre Feet) | Height (Feet) |
Very Small | <50 | and <25 |
Small | >=50 and <1000 | or >=25 and <40 |
Intermediate | >=1000 and <50,000 | or >=40 and <100 |
Large | >=50,000 | or >=100 |
C. Hazard Potential Classification. The classification for potential hazard shall be in accordance with the table below. The hazards pertain to potential loss of human life or property damage in the event of failure or improper operation of the dam or appurtenant works. Probable future development of the area downstream from the dam that would be affected by its failure shall be considered in determining the classification. Dams shall be subject to reclassification if the Department determines that the hazard has changed.Hazard Classification | Hazard Potential |
High Hazard | Dams located where failure will likely cause loss |
Significant Hazard | Dams located where failure will not likely cause |
Low Hazard | Dams located where failure may cause minimal |
D. Exemptions. The following types of dams are exempt from the Dams and Reservoirs Safety Act and the regulations pertaining thereto: 1. Unless the hazard potential as determined by the Department is such that dam failure or improper reservoir operation may cause loss of human life, any dam which is or shall be (a) less than twenty-five feet in height from the natural bed of the stream or water course measured at the downstream toe of the dam, or twenty-five feet from the lowest elevation of the outside limit of the dam, if it is not across a stream channel or water course, to the maximum water storage elevation and (b) has or shall have an impounding capacity at maximum water storage elevation of less than fifty acre-feet.2. Any dam owned or operated by any department or agency of the federal government.3. Any dam owned or licensed by the Federal Energy Regulatory Commission, the South Carolina Public Service Authority, the Nuclear Regulatory Commission, the United States Army Corps of Engineers, or other responsible federal licensing agencies considered appropriate by the Department.4. Any dam upon which the South Carolina Department of Transportation or county or municipal governments have accepted maintenance responsibility for a road or highway where that road or highway is the only danger to life or property with respect to failure of the dam.5. Any dam, which in the judgement of the Department, because of its size and location could pose no significant threat of danger to downstream life or property. Upon request, Certificates of Exemption (DHEC Form 2601(6/94) are available from the Department for dams in this category.E. Dams in Series. If an upstream dam has the capability to create failure in a downstream dam because of its failure flood wave, it shall have the same or higher hazard classification as the downstream dam. If the failure flood wave of the upstream dam will not cause failure of the downstream dam, the upstream dam may have a different hazard potential classification from the downstream dam.Amended by State Register Volume 5, eff June 5, 1981; State Register Volume 17, Issue No. 5, Part 3, eff May 28, 1993; State Register Volume 21, Issue No. 7, eff July 25, 1997.