S.D. Codified Laws § 38-8-50
A conservation district, and the supervisors thereof, shall have the power, in addition to others granted in other sections of this chapter, to develop annual and long range ten-year comprehensive plans, which plans may be prepared with the cooperation and assistance of the State Planning Commission and other state and federal agencies, for the conservation of all renewable natural resources and for the control and prevention of soil erosion, flood prevention, or the conservation and development, utilization, and disposal of soil and water within the district, including but not limited to, the specification of engineering operations, methods of cultivation, pollution abatement, cropping systems, and changes in the use of land for all purposes. Such plans shall be developed and modified each year to maintain a ten-year projection.
SDCL 38-8-50