S.D. Codified Laws § 9-21-7
In the event of the failure to provide by the annual appropriation ordinance, sufficient revenue to enable the municipality to conduct the indispensable functions of government in any department, or to discharge any duty which it is the lawful duty of the municipality to discharge and which requires the incurring of liabilities or expenditures of funds for a purpose or object for which no provision has been made in the annual appropriation ordinance for such fiscal year, and when any of such occasions arise the governing body of such municipality may make, approve and adopt a supplemental appropriation ordinance, providing therein for appropriations for any or such purposes in such amounts as said governing body may determine necessary and such supplemental appropriation ordinance shall set out in detail each item for which an appropriation is made and the amount thereof. The adoption of such supplemental appropriation ordinance shall be governed by the same laws pertaining to the adoption of the annual appropriation ordinance.
SDCL 9-21-7