§ 784.29 - Diversions.

§ 784.29 What information must I include in the surface-water runoff control plan?

Your application must contain a surface-water runoff control plan that includes the following -

(a)

(1) An explanation of how you will handle surface-water runoff in a manner that will prevent peak discharges from the proposed permit area, both during and after mining and reclamation, from exceeding the premining peak discharge from the same area for the same-size precipitation event. You must use the appropriate regional Natural Resources Conservation Service synthetic storm distribution or another scientifically defensible method approved by the regulatory authority that takes into account the time of concentration to estimate peak discharges.

(2) The explanation in paragraph (a)(1) of this section must consider the findings in the determination of the probable hydrologic consequences of mining prepared under § 784.20 of this part.

(b) A surface-water runoff monitoring and inspection program that will provide sufficient precipitation and stormwater discharge data for the proposed permit area to evaluate the effectiveness of the surface-water runoff control practices under paragraph (a) of this section. The surface-water runoff monitoring and inspection program must specify criteria for monitoring, inspection, and reporting consistent with § 817.34(d) of this chapter. The program must contain a monitoring-point density that adequately represents the drainage pattern across the entire proposed permit area, with a minimum of one monitoring point per watershed discharge point.

(c) Descriptions maps, and cross-sections of runoff-control structures. A runoff-control structure is any man-made structure designed to control or convey storm water runoff on or across a minesite. This term encompasses the entire surface water control system and includes diversion ditches, drainage benches or terraces, drop structures or check dams, all types of conveyance channels, downdrains, and sedimentation and detention ponds and associated outlets. It does not include swales or reconstructed perennial, intermittent, or ephemeral stream channels.

(d) An explanation of how diversions will be constructed in compliance with § 817.43 of this chapter.

Diversions.

Each application shall contain descriptions, including maps and cross sections, of stream channel diversions and other diversions to be constructed within the proposed permit area to achieve compliance with § 817.43 of this chapter.

[44 FR 15366, Mar. 13, 1979. Redesignated and amended at 48 FR 43989, Sept. 26, 1983; 81 FR 93355, Dec. 20, 2016; 82 FR 54958, Nov. 17, 2017]