Classes A, B, and C dams are defined in Section 3.4.b of Title
38 Series 4 of the Coal Related Dam Safety Rule. This is taken
from the Department of Environmental Protection Division of Mining
- 3.4.b.1. Class A Dams: Class A dams are those dams located
in rural or agricultural areas where failure may damage non-residential
and normally unoccupied buildings, rural or agricultural land,
or secondary highways. Failure of Class A dam would cause only
a loss of the dam itself and a loss of property use, such as
use of related roads, with little additional damage to adjacent
property. Any impoundment exceeding twenty-five (25) feet in
height measured at the downstream toe or two hundred (200) acre-feet
storage volume or having a watershed exceeding five hundred (500)
acres should not be class A dam.
- 3.4.b.2. Class B Dams: Class B dams are those
dams located in predominantly rural or agricultural areas
where failure may damage isolated homes, primary highways, or
minor railroads or may cause the interruption of public utility
services. Failure of a Class B dam may cause great damage to
property and project operations. Loss of human life resulting
from failure of a class B dam must be unlikely.
- 3.4.b.3. Class C Dams: Class C dams
are those dams located where failure may cause a loss of
human life or serious damage to homes, industrial and commercial
buildings, important public utilities, primary highways or main
haul roads. This classification must be used if failure would
cause possible loss of human life.
Mine Safety and Health Administration Hazard
- Low Hazard Potential: Facilities in rural areas where failure
would cause only slight damage, such as to farm buildings,
forest, agricultural land, or minor roads.
- Moderate Hazard Potential: Facilities
in predominately rural areas where failure may damage isolated
homes or minor railroads, disrupting services or important
Hazard Potential: Facilities whose failure could reasonably
be expected to cause loss of human life, serious damage to houses,
industrial and commercial buildings, important utilities,
highways, and railroads.