510 EXPERIMENT STATION RECORD. 



Water rights on interstate streams: The Platte River and tributaries, 

 R. P. Teele and E. Mead ( u . S. Dept. Agr., Office Expt. Stas. Bid. 157, pp. 118, pis. 

 4, figs. 3). — This report is a discussion of two features of stream ownership and con- 

 trol; one is the division of the water of the stream between States, and the other is 

 the relation of the rights of appropriators of water and of riparian proprietors to each 

 other where both exist on the same stream. 



The total area irrigated by the Platte River and its tributaries is about 2,000,000 

 acres. Most of the irrigated lands upon the South Platte River are in Colorado, but 

 the farmers of other States make extensive use of the waters of the North Platte. 

 The area irrigated from the North Platte and its tributaries in the three States is as 

 follows: Colorado, 157,965 acres; Wyoming, 413,000 acres; Nebraska, 338,220 acres. 

 With these important interests in three States and with a tendency for the farmers 

 farther up the river to increase their diversions of water, the importance of some 

 form of interstate agreement or Federal regulation becomes apparent. 



The average flow of the North. Platte at Guernsey from April to September is 4,013 

 cu. ft, per second, and the decreed rights to water from the North Platte and Platte 

 below the point of its junction with the South Platte aggregate 11,173 cu. ft. per 

 second, or nearly three times the supply. This situation is well understood, but the 

 need of water and its prospective value is so great that appropriations are being 

 made more aggressively than ever before. 



Fortunately it happens that the physical conditions are such that Colorado will 

 not be able to appropriate much of the water now being used by the Wyoming 

 farmers. The irrigable areas along the North Platte in Colorado are very limited 

 and most of the appropriations from the North Platte in Wyoming are in the last 30 

 miles of the river's course in that State, and because of the long distance between 

 this irrigated region and Colorado it is not probable that use in Colorado will affect 

 Wyoming irrigators. In general it seems to be true that a very large proportion of 

 the water diverted for purposes of irrigation finds its way back sooner or later to the 

 river, so that the same water may be used several times along the course of the 

 stream, and the higher up the stream the water is first diverted the greater the area 

 which may be made productive by its use. 



While the diversions of water from the North Platte River in Colorado seem to 

 make no difference in the flow of that river near the Wyoming-Nebraska line, it 

 seems to be true also that the diversions of water in Wyoming near the Wyoming- 

 Nebraska line have little influence upon the flow of the river 180 miles below the 

 State line near the city of North Platte. A large number of irrigators and ditchmen 

 in the vicinity of North Platte and along the ditches below r that city were 

 interviewed and none of them seemed to feel that the diversions in the upper States 

 diminished their supply of water. 



The general sentiment seemed to be that the increased use of water in Wyoming 

 and along the upper valley in Nebraska would improve rather than injure the sup- 

 ply for the ditches below. The supply for these ditches has always been short in 

 the late summer, and can not be much worse. There owners, therefore, look with 

 favor upon the enlarged use of water above in flood seasons in the hope that the 

 return seepage will maintain the flow below in the late summer. 



So important is the element of return seepage that it is believed there is little like- 

 lihood of any interstate conflict on the North Platte unless it should be between 

 ditches heading close together immediately above and below the State line. If the 

 State of Wyoming should grant the right to divert all of the water flowing in the 

 river immediately above the State line, without regard to the diversions which have 

 been made under the laws of Nebraska just below the State line, the agricultural 

 interests of the latter State would be seriously injured, but if the prior rights in 

 Nebraska are recognized by Wyoming no serious conflict should arise. 



