S.D. Codified Laws § 1-16J-15
The State of South Dakota pledges to and agrees with the holders of the revenue bonds and notes of the authority issued pursuant to this chapter that the state will not limit or decrease the rights and powers vested in the authority by this chapter so as to impair the terms of any contract made by the authority with such holders or in any way impair the rights and remedies of such holders until such revenue bonds, notes, or other instruments, together with interest thereon, with interest on any unpaid installments of interest, and all costs and expenses in connection with any action or proceedings by or on behalf of such holders, are fully met and discharged. The authority may include these pledges and agreements of the state in any contract with the holders of revenue bonds, notes, or other instruments issued pursuant to this section.
SDCL 1-16J-15