Administrative Rules of Montana
Department 17 - ENVIRONMENTAL QUALITY
Chapter 17.24 - RECLAMATION
Subchapter 17.24.6 - Strip and Underground Mine Reclamation Act: Transportation Facilities, Use of Explosives, and Hydrology
Rule 17.24.636 - SPECIAL REQUIREMENTS FOR TEMPORARY DIVERSIONS
Current through Register Vol. 6, March 22, 2024
(1) A temporary diversion must be constructed to pass safely the peak runoff from a precipitation event with a 10-year, 24-hour recurrence interval, or a larger event as specified by the department.
(2) If channel lining is required to prevent erosion, the channel lining must be designed using standard engineering practices to safely pass design velocities.
(3) Freeboard must be as specified by the department, but no less than 1.0 foot.
(4) Energy dissipators must be installed in streams where exit velocity of the diversion is greater than that of the receiving stream.
(5) Whenever streamflow is allowed to be diverted, the stream channel diversion must be designed, constructed, and removed in accordance with the following requirements:
(6) When no longer needed to achieve the purpose for which it was authorized, a temporary diversion must be removed and the affected land regraded, resoiled, and revegetated, in accordance with subchapters 5 and 7. At the time a diversion is removed, downstream water treatment facilities previously protected by the diversion must be modified or removed to prevent over-topping or failure of the facilities. This requirement does not relieve the operator from responsibility for maintenance of a water treatment facility otherwise required under this subchapter or the permit.
AUTH: 82-4-205, MCA; IMP: 82-4-231, MCA