Rule 4 Standard Measurements of Water

Rule 4(a). Converting measurements. The department will use the following conversions in determining equivalent flow rates and volumes:

(1) forty (40) statutory or miner's inches equals 1.0 cubic foot per second (cfs);

(2) one (1) miner's inch equals 11.22 gallons per minute (gpm);

(3) one (1) cubic foot per second (cfs) equals 448.8 gallons per minute (gpm); and

(4) one (1) acre-foot of water equals 325,851 gallons.

Rule 4(b). Units of water measurement. The decree abstract and the department's summary report to the water court shall identify units of water measurement in compliance with § 85- 2-103, MCA, as follows:

(1) for flow rates:

(i) less than one (1) cfs will be in units of gallons per minute;

(ii) equal to or greater than one (1) cfs will be in units of gallons per minute or cubic feet per second, as claimed or based on the customary reference for the method of diversion;

(2) volumes will be in acre-feet or gallons.