S.D. Codified Laws § 46A-14-72
The watershed district may purchase such real estate or easement therein as it may need and if it cannot agree on the purchase price on any needed real estate or easement therein, it may condemn the same. If the watershed district finds it expedient or necessary for the maintenance of any part of its improvement already constructed to add thereto further construction in the nature of settling basins, conservation lakes, or other improvements, the watershed district, if not able to agree with the landowner on the terms for the acquisition of the interest in land needed or the yearly cash rental of any premises taken and used for such purpose, may condemn for the purpose of fixing the amount to be paid for the interest in the land or the yearly rental for the land so taken. The appraisal of the premises involved shall be made by a committee composed of the aggrieved, a district manager, and these two shall elect a third member. If the watershed district takes or damages the real estate of any minor or protected person, the conservator of such minor or protected person may agree and settle with the watershed district for all damages or claims by reason of taking such real estate or easement, and may give valid releases and discharge therefor.
SDCL 46A-14-72