SDCL § 7-21-26: Excessive debts, liabilities, and payments void.

All orders, authorizations, allowances, contracts, payments, or agreements or liabilities to pay, made or attempted to be made in violation of this chapter, shall be void and shall never be the foundation of a claim against any county or against any institution or agency thereof, and all warrants, certificates, orders, or other evidences of indebtedness drawn or issued for the purpose of paying any indebtedness or liabilities incurred or created or attempted to be incurred or created in violation of the provisions of this chapter shall be void.