S.C. Code Regs. § § 61-119.D.3
Each permittee must prepare and maintain on site, available for inspection, an operational and contingency plan to promote an adequate water supply from the surface water during times when the actual flow of the surface water is less than the minimum instream flow for that particular surface water segment. The existence of a plan is deemed to be an enforceable part of the permit under which the permittee is withdrawing surface water and shall be deemed to control a permitted surface water withdrawal in situations where the actual flow of the surface water is less than the minimum instream flow for that particular stream segment. For an existing surface water withdrawer, the operational and contingency plan will only address appropriate industry standards for water conservation. If initial permits issued under this section are expanded, contingency plans for existing surface water withdrawers must meet the requirements of section E.4 for the volume permitted over and above that of the initial permit.
S.C. Code Regs. § 61-119.D.3