S.D. Codified Laws § 46A-14-47
The managers shall within a reasonable length of time after qualifying, adopt an overall plan for improvements within the district for reclamation, drainage, erosion, and flood control, and improvement of lands, soils, waters, forests, wildlife, and all other authorized purposes. The plan finally adopted shall be made in conjunction with the advisory committee established pursuant to § 46A-14-40 and in consultation with the district supervisors of each conservation district in the watershed district, but the managers have final authority and full responsibility. This plan shall be designated the general improvement plan for the watershed district. The general improvement plan shall consist of a map showing the area to be benefited; the location of the proposed works of improvement; the location of buildings, roads, streams, and other topographic features as are pertinent to show the relation of the proposed works of improvement to the area of the district; and a narrative in which are stated the estimated benefits that will result and the proposed method of financing and accomplishing the work to be done. Upon receipt of a copy of the general improvement plan, the Board of Water and Natural Resources shall examine the plan and within thirty days transmit a report of their recommendations to the managers.
Before formation of a watershed district, requests for planning assistance, development of watershed work plans, and similar considerations may be undertaken by steering committees of local people with sponsoring assistance by conservation districts as permitted under state law and in accordance with federal laws. Such plans may be considered as the preliminary general improvement plan until the final general improvement plan is adopted as provided in this section.
SDCL 46A-14-47