S.D. Codified Laws § 46A-7-1
For the purpose of defraying the expenses of the organization of an irrigation district, and for the purpose of defraying all expenses incurred in formulating a general plan for the proposed operation of an irrigation district including surveys, maps, estimates, examinations, and plans made in order to demonstrate the practicability of such general plan, all as authorized by §§ 46A-5-2 and 46A-5-3, and for the purpose of defraying all expenses related to the care, operation, management, repair, and improvement of such portions of its canal and works as are completed and in use, including salaries of officers and employees, the board of directors of the district may either fix rates of tolls and charges and collect the tolls and charges from all persons using such works for irrigation or other purposes, or may provide for the payment of such expenditures by assessments, or by both tolls and assessments. If by assessment, the levy shall be made upon the completion and equalization of the assessment roll in accordance with the benefit received; and the board has the same powers and functions for the purposes of the levy as are now possessed by boards of county commissioners in this state. The assessment shall be collected as provided in this chapter.
SDCL 46A-7-1