A low-quality fishery water is defined as a stream classified for the beneficial use of warmwater semipermanent fish life propagation or warmwater marginal fish life propagation, or fish and wildlife propagation, recreation, and stock watering. The design low flow for a low-quality fishery or irrigation water is the minimum 7-day average low flow that can be expected to occur once in every five years (7Q5) or 1.0 cubic foot per second, whichever is greater. During these low flow periods, the water quality criteria set forth in §§ 74:51:01:48 and 74:51:01:49, inclusive, and §§ 74:51:01:52 and 74:51:01:53 do not apply to the water but all surface water discharge permit limits remain in force. If one cubic foot per second is greater than the flow expected to occur once every five years (7Q5), the toxic pollutant standards contained in Appendix B continue to apply to the water to the point where the flow in the stream drops to or below the 7Q5.
S.D. Admin. R. 74:51:01:30
General Authority: SDCL 34A-2-11, 34A-2-93.
Law Implemented: SDCL 34A-2-10, 34A-2-11, 34A-2-22.