S.D. Codified Laws § 9-44-6
The municipality may agree to pay any part not exceeding one-half of the principal of and interest on municipal improvement bonds by ad valorem taxation on all property within the municipality. Such part of the principal shall be a general obligation indebtedness of the municipality and shall not, together with other indebtedness as of the date of issue of the bonds, exceed any constitutional limitation. In computing the municipality's indebtedness at any time after the issuance of the bonds, the same fraction of the principal amount of the bonds then outstanding, less an equal fraction of any moneys in the fund of the improvement, shall be included. Before delivery of the bonds the governing body shall levy and cause to be certified to the county auditor a direct, annual, irrepealable, ad valorem tax, to be spread upon the tax rolls for the same years as the special assessments, in amounts sufficient to pay the proportionate part of each installment of principal and interest as the same matures. Said tax may not exceed the part of principal and interest so payable by more than five percent, but shall not be subject to any other tax levy limitation provided by law. The levy of taxes or assumption of payment of a part of principal and interest requirements in excess of the limitations herein shall be invalid only as to such excess.
SDCL 9-44-6