Laserfiche WebLink
Colorado Line to Pathfinder Reservoir. In the region between the Colorado - Wyoming line and Pathfinder <br />appropriation rights cover about 272, 000 acres, 149,400 of which are irrigated. But of those only 9,400 <br />acres are irrigated from the main stream, the balance being irrigated from tributaries. The consumptive use <br />rate is about 1 acre foot per acre. Over two - thirds of the volume of diversions (main stream and tributaries) <br />and 88 per cent from the main stream are senior to the North Platte Project. They are in the main junior to <br />the State Line Canals in Nebraska. Those projects junior to Pathfinder have been operated since 1930 in <br />violation of its priority. The Special Master found that there is no present prospect of any large expansion <br />of irrigation in this area, though five additional projects have been contemplated, some of them being <br />partially constructed. The accretions to the river from tributaties in this section are very large -about <br />790,240 acre feet net. Land consumption is 16 per [325 U.S. 589, 602] cent of the net accretions, while <br />that of rights junior to Pathfinder is about 5.6 per cent of the net. <br />North Platte Project. The priority of Pathfinder is December 6, 1904 and of Guernsey April 20, 1923. <br />Between Pathfinder and the Nebraska state line there are 32 canals on the main river which have priorities <br />senior to Pathfinder. The State Line Canals in Nebraska also are senior to Pathfinder. And Guernsey is <br />junior to all canals below it down to the Nebraska line. The percentage of rights in each section senior and <br />junior to the North Platte Project are as follows: <br />Percentage Percentage Senior Junior North Park 67 33 Colorado State Line to Pa hfinder Reservoir 88 12 <br />Pathfinder Reservoir to Whalen 52 48 Whalen to (Nebraska State Line Wyoming private canals) 919 <br />Nebraska State Line Canals 100 0 <br />Under Wyoming law reservoirs in storing water must observe the priority of all senior, Wyoming canals <br />below them on the main river. Kendrick Project. Seminoe Reservoir has a priority of December 1, 1931; <br />Casper Canal, July 27, 1934 (natural flow); Alcova Reservoir, April 25, 1936. Apart from minor exceptions <br />Seminoe is junior to every appropriator from Alcova to the Tri -State Dam. The project is expected to <br />operate chiefly on storage water. In its early stages its water requirements will be heavier than they will be <br />later, due to ground absorption and storage. When the project has been in operation a while, the depletion <br />during the irrigation season will be about 122,000 acre feet, except as water storel in non - irrigation season <br />is used. The Special Master found, however, that without violating the Pathfinder priority, the Kendrick <br />project could have stored no water since 1930 and can store none in the future if present conditions <br />continue. He also [325 U.S. 589, 603] found that under the average conditions which prevailed from 1895 <br />to 1939 water could be conserved by Seminoe and Alcova without violation of the priorities between <br />Pathfinder and Tri -State Dam and in sufficient quantities to supply Kendrick and to leave considerable <br />return flow to the river in the irrigation season. There are in the first unit of the project two sump areas into <br />which return water will flow and from which the United States has constructed drainage ditches so as to <br />return the water to the river. On the uncompleted unit three sump areas are planned. These are designed to <br />return to the river water which otherwise would be lost. <br />Pathfinder to Whalen. The total land irrigated in this section is in excess of 55,000 acres, of which about <br />14,000 acres are supplied from the main river. Alfalfa, sugar beets, potatoes, and grains are the principal <br />irrigated crops. There are 60 canals taking out of the main river with priorities ranging from 1887 to 1937. <br />In terms of acreage about 48 per cent of the rights on the river in this section are junior to the North Platte <br />Project. All except one are junior to the Tri -State canal and most of them are junior to the other Nebraska <br />state line canals. The irrigation projects on the river average not over 160 acres. The consumptive use rate <br />is about 1.1 acre feet per acre. The diversion rate of 2.5 acre feet per acre is deemed adequate. But during <br />the 1931 -1940 period the average seasonal diversion rate for the section was only 2 acre feet, since in low <br />stages of flow some of the ditches are unable to divert any water. But at the rate of 2.5 acre feet the total <br />seasonal headgate diversion for the 14, 000 acres is 35,000 acre feet of which 18,200 acre feet would be <br />returned to the river. Of that return all but 15 per cent (2,730 acre feet) would occur during the irrigation <br />season. The tributary inflow is greater than river depletion due to irrigations and other losses. The average <br />annual net gain from 1931 -1940 was 64,200 acre feet. During [325 U.S. 589, 604] the 1931 -1940 period, <br />the maximum seasonal average consumption out -of- priority in relation to the Nebraska State Line Canals <br />was found by the Special Master to be 5,400 acre feet. With probable minor exceptions there are no further <br />possibilities for irrigation developments in this section. <br />