Hazard Classification

01. Hazard Classification. The following table describes categories of hazard used by the Department to classify dams relative to the potential failure consequences estimated for downstream locations. The listed hazard classifications are meant to serve as guidelines for implementing design, construction, and operation criteria, subject to final interpretation by the Director: Dam Size Classification Height Storage Capacity Small Dams and Reservoirs Ten (10) feet or more but less than twenty (20) feet and Fifty (50) acre-feet or more but less than one hundred (100) acre-feet. Intermediate Dams and Reservoirs Twenty (20) feet or more but less than forty (40) feet or One hundred (100) acre-feet or more but less than four thousand (4,000) acre-feet. Large Dams or Reservoirs Forty (40) feet or more or Four thousand (4,000) acre-feet or more. Hazard Classification Downstream Development Estimated Loss of Life Economic Losses Low Undeveloped property, no permanent or permanently occupied structures for human habitation. No loss of life Low economic losses generally lim- ited to the owner; low damage to or disruption of transportation, utilities, or other public facilities or values including environmental loss. IDAHO ADMINISTRATIVE CODE IDAPA 37.03.06 Department of Water Resources Safety of Dams Rules Section 030 Page 7 (3-30-23) 02. Determination of Hazard Classification. The Director shall determine the hazard classification of a new or existing dam governed by these rules. Hazard classifications shall be assigned to new and existing dams based on the severity of failure consequences exclusive of the size or the physical condition of the dam. The designated hazard classification, as established by the Director, shall determine the applicable design and operational standards applied to the dam. (3-30-23) 026. – 029. (RESERVED)