SDCL § 46-1-7: Standards of measurement--Flow of water--Volume of water--Miner's inch.

The standard of the measurement of the flow of water shall be the cubic foot per second of time; and the standard of measurement of the volume of water shall be the acre-foot, being the amount of water upon an acre covered one foot deep, equivalent to forty-three thousand five hundred sixty cubic feet. The miner's inch shall be regarded as one-fiftieth of a cubic foot per second in all cases, except when some other equivalent of the cubic foot per second has been specially stated by the contract or has been established by actual measurement or use, or by court decree.