Idaho Code § 42-1710
It is the intent of the legislature by this act to provide for the regulation of construction, maintenance and operation of all dams, reservoirs and mine tailings impoundment structures exclusively by the state to the extent required for the protection of public safety. All dams, reservoirs and mine tailings impoundment structures in the state are under jurisdiction of the department of water resources. The department of water resources, under the police power of the state, shall supervise the construction, enlargement, alteration, repair, maintenance, operation and removal of dams, reservoirs and mine tailings impoundment structures for the protection of life and property. The department of water resources may enter into agreements with other state agencies having jurisdiction over water storage structures to limit duplication of inspection, review and regulation of such structures.
Idaho Code § 42-1710