SDCL § 46-5-25: Diligent prosecution of construction work--Forfeiture of rights--Extension.

The work of construction shall be diligently prosecuted to completion. If one-fifth of the work is not completed within one-half the time allowed, as determined by the Water Management Board, the board may accept and approve an application for the use of any of the waters included in the permit issued to the prior applicant, and the right to use the waters under the former permit are forfeited. However, the Water Management Board shall allow an extension of time at the request of the prior applicant, equal to the time during which work was prevented by the operation of law beyond the power of the applicant to avoid. This section does not apply to permits or licenses issued under § 46-5-8.1.