S.D. Codified Laws § 6-8B-53
Crossover refunding bonds may be issued by a public body without regard to the limitations in §§ 6-8B-46 and 6-8B-48. The proceeds of crossover refunding bonds less any proceeds applied to payment of the costs of their issuance, shall be deposited in a debt service fund irrevocably appropriated to the payment of principal of and interest on the refunding bonds until the date the proceeds are applied to payment of the bonds to be refunded. The debt service fund shall be maintained as an escrow account with a suitable financial institution within or without the state, which has trust powers and which has complied with the applicable provisions of §§ 51A-5-7 to 51A-5-10, inclusive, and amounts in it shall be invested in securities described in this section. Excess proceeds, if any, of the tax levy made with respect to the bonds to be refunded, and any other available amounts, may be deposited in the escrow account. In the resolution authorizing the issuance of crossover refunding bonds, the governing body may pledge to their payment any source of payment of the bonds to be refunded. In the case of general obligation bonds, taxes shall be levied and appropriated to the debt service fund in the amounts needed, together with estimated investment income of the debt service fund and any other revenues available upon discharge of the bonds refunded, to pay when due the principal of and interest on the refunding bonds. The levy so imposed may be reduced by earnings to be received from investments on hand in the debt service fund to the extent the applicable recording officer certifies to the county auditor that the earnings are expected to be received in amounts and at such times as to be sufficient, together with the remaining levy, to satisfy the purpose of the levy. Any taxes levied for the payment of principal of or interest on the bonds to be refunded shall continue until all of the bonds to be refunded have been fully paid.
SDCL 6-8B-53