Montana Title 85. Water Use § 85-2-103. Measurement of water

(1) After July 1, 1899, a cubic foot of water (7.48 gallons) per second of time shall be the legal standard for the measurement of water in this state.

(2) Where water rights expressed in statutory or miner's inches have been granted, 100 statutory or miner's inches shall be considered equivalent to a flow of 2.5 cubic feet (18.7 gallons) per second, 200 statutory or miner's inches shall be considered equivalent to a flow of 5 cubic feet (37.4 gallons) per second, and this proportion shall be observed in determining the equivalent flow represented by any number of statutory or miner's inches.

(3) The provisions of this section shall not affect or change the measurement of water decreed by a court prior to July 1, 1899, but such decreed water shall be measured according to the law in force at the time such decree was made and entered.