49-255.05. Best management practices for activities within non-WOTUS
A. The director shall adopt by rule best management practices and notification requirements to ensure that the activities prescribed in this section do not violate applicable surface water quality standards. The director may include only those best management practices that extend to:
1. Activities conducted within the ordinary high watermark of perennial or intermittent non-WOTUS protected surface waters.
2. Activities conducted within the bed and banks of waters that materially impact downstream non-WOTUS protected surface waters. The director shall determine through rulemaking what constitutes a material impact and that rulemaking shall be based on factors that include distance and topography.
3. Activities that are not already regulated under this title.
B. The director may not adopt best management practices and notification requirements for the following:
1. Discharges to a non-WOTUS protected surface water incidental to a recharge project.
2. Established or ongoing farming, ranching and silviculture activities such as plowing, seeding, cultivating, minor drainage or harvesting for the production of food, fiber or forest products or upland soil and water conservation practices.
3. Maintenance but not construction of drainage ditches.
4. Construction and maintenance of irrigation ditches.
5. Maintenance of structures such as dams, dikes and levees.