10 



But physical conditions are as important as laws and decisions in 

 determining the relation of rights to water from the same stream, 

 and consequently rainfall, the stream flow, the diversions from the 

 streams, and the return seepage from irrigated lands have all been 



studied. 



The field work on which this report is based was done during the 

 summer of 1003. Mr. W. B. Dunton made a study of the laws and de- 

 cisions of the three States; Mr. C. E. Tait and Prof. (). V. P. Stout 

 made measurements of return seepage; Mr. Frank Adams collected 

 records of diversions and crop returns, and Mr. W. F. Bartlett col- 

 lected records of stream flow. Each of these agents made a study of 

 a particular phase of the general question in hand. It was found 

 impracticable to publish the reports entire, but it Avas decided rather 

 to bring the essential points together in this one discussion. The 

 duty of bringing the results together and determining their bearing 

 on the question being studied was assigned to the writer, to whom the 

 reports of the agents named were submitted. After going over these 

 reports, the writer spent the summer of 190-1: in the field collecting 

 such information as seemed to be needed to make the general discus- 

 sion complete and getting such a personal knowledge of the field 

 covered as is necessary to an intelligent discussion of its ])roblems. 



It is not possible to give in the text credit for each fact taken from 

 these reports, and therefore general credit is given here. Most of the 

 information regarding court decisions and rights to the streams is 

 taken from the report of Mr. Dunton, the seepage measurements in 

 Colorado and Wyoming are taken from the report of Mr. Tait, seep- 

 age measurements in Nebraska are taken from the report of Pro- 

 fessor Stout, the records of diversions and of crop returns are taken 

 from the report of ^Ir. Adams, and most of the records of stream 

 discharges are supplied by Mr. Bartlett. 



PRESENT CONDITIONS. 



The controlling factor in the necessity for irrigation along the 

 Platte River is the rainfall. The precipitation is heavier in the 

 mountains, lighter ou the plains at the base of the mountains, and 

 o-rudually increases toward the Missouri. This is shown in the 

 following table, which gives the normal precijDitation at stations 

 along the rivers from near the summit of the C(mtinental Divide to 

 the Missouri. The data are taken from the reports of the United 

 States Weather Bureau. 



