North Dakota Administrative Code
Title 89 - Water Commission
Article 89-04 - Water Management Plans for Surface Coal Mining Operations
Chapter 89-04-07 - Requirements for Sediment Control Devices
Section 89-04-07-03 - Requirements for larger ponds
Current through Supplement No. 394, October, 2024
If a sedimentation pond has an embankment that is more than twenty feet [6 meters] in height, as measured from the upstream toe of the embankment to the crest of the emergency spillway, or has a storage volume of twenty acre-feet [24.6 cubic dekameters] or more, the following additional requirements shall be met:
1. An appropriate combination of principal and emergency spillways shall be provided to safely discharge the runoff resulting from a hundred-year, six-hour precipitation event, or larger event as specified by the state engineer.
2. Ponds shall be designed and constructed with an acceptable static safety factor of at least one and one-half for maximum design flood elevation of the pool to ensure embankment slope stability.
3. The minimum top width of the embankment shall not be less than the quotient of (H+35)/5 where H is the height of the embankment as measured from the upstream toe of the top of the embankment.
4. Ponds shall have appropriate barriers to control seepage along conduits that extend through the embankment.
General Authority: NDCC 28-32-02, 61-02-11, 61-03-13
Law Implemented: NDCC 61-02-14, 61-16.1-38
