S.D. Codified Laws § 46A-8-7
Such associations have the first and prior lien for all unpaid assessments on the lands of the shareholder against which the assessments are levied, and for all deferred payments on the water right appurtenant to the lands. The lien is in all respects prior to any other liens created or attempted to be created by the owner and possessor of the lands. The lien shall remain in effect until the last deferred payment for the water right and any unpaid assessments levied by the association against the land are fully paid and satisfied, according to the terms of the contract under which the water right was acquired, the provisions of this chapter, and the bylaws of the association relating to assessments. The lien shall be enforced by the association by the foreclosure and sale of the lands, or so much thereof as may be necessary, in the manner provided by law for the foreclosure of mortgages on real property.
SDCL 46A-8-7