(a) Natural watercourses as designated by law or regulation shall not be blocked with a stand, dam, weir, hedge, or other water diversion structure to supply an aquaculture facility that in any way prevents or fails to maintain the free passage of anadromous or indigenous fish.
(b) Residual flow in a natural watercourse below the point of water withdrawal supplying an aquaculture operation shall be sufficient to prevent destruction or serious diminution of downstream fishery habitat and shall be consistent with rules adopted by the Environmental Management Commission.