S.D. Codified Laws § 13-39-55

For the purpose of paying any administrative, planning, operating, or capital expenses incurred or to be incurred, a center board shall assess each participating school district its proportionate share based upon its enrollment in grades nine through twelve as compared to the total enrollment in grades nine through twelve of all participating school districts in the multidistrict center. Each participating school district shall remit payment of its assessment to the center board no later than thirty days after the official date of receipt as noted on the assessment notice.