S.D. Codified Laws § 1-16G-62
The affidavit for reinvestment payment as required by § 1-16G-61 shall be filed no later than six months after the completion of the project. If the affidavit for reinvestment payment is not timely filed, the person is ineligible for any reinvestment payment provided by §§ 1-16G-56 to 1-16G-68, inclusive. If the person filing the affidavit for reinvestment payment knowingly makes any material false statement or report in the affidavit for reinvestment payment, the person is ineligible for any reinvestment payment provided by §§ 1-16G-56 to 1-16G-68, inclusive.
No project costs that occur after three years from the construction date are eligible to be included in the final project cost determination for any reinvestment payment provided by §§ 1-16G-56 to 1-16G-68, inclusive, unless an extension is granted at the sole discretion of the board, which extension may not extend beyond four years from the construction date.
SDCL 1-16G-62