(1945 state law providing for exemptions from permit requirement for certain types of withdrawals of groundwater applies to withdrawals for stock-watering purposes and does not limit such withdrawals to any particular quantity; withdrawals at issue involved between 450,000 and 600,000 gallons per day for 30,000-head cattle feedlot; at time of enactment in 1945 legislature could have reasonably believed that stock-watering was of significant importance and impact of such watering slight; dissent opined that legislature never intended that statute would allow such large withdrawals with no examination of whether existing rights impaired or public welfare harmed).