91 



appropriator. That is, the right of an appropriator at any time 

 would be limited to the right to continue the beneficial use which 

 he had made up to that time, and any enlarged use or diU'erent use 

 would be later and therefore subject to any rights acciuired by others 

 in the meantime. This would be the logical result of basing rights 

 absolutely on beneficial use, and this principle is at the foundation 

 of water rights in the Platte Valley, although it is very much 

 obscured by modifications adopted in applying it. 



It would be extremely difficult to make and enforce a table of prior- 

 ities showing just when each enlargement in use by each approi)ria- 

 tor took place. Under existing practice a single appropriator may 

 have two or three or more rights with ditferent priorities, but if each 

 canal had a separate priority for each piece of land as it was brought 

 under cultivation, and if for each piece of land there was a series of 

 rights with different dates, as the character of the crops grown and 

 therefore the time of use and quantity used changed the distribution 

 of the water of a stream in accordance with those rights would be 

 so intricate and burdensome that the water would be hardly worth 

 the cost of distribution. This has been avoided by basing rights on 

 original construction and subsequent enlargements of works. In 

 Colorado the right is dated at the time of beginning construction, 

 the measure of the right being the carrying capacity of the works, 

 provided the water is put to a beneficial use within a reasonable time. 

 In Wyoming and Nebraska the measure of the right is the need of the 

 area of land for which an application is approved by the State engi- 

 neer, and the time within which the water must be put to the bene- 

 ficial use is fixed in the approval of the application. If the water 

 is put to use within a reasonable time in Colorado, and within the 

 prescribed time in the other States, the right to the whole volume dates 

 from the first step in its acquirement. This is known as the right 

 of relation, and is a modification of the principle of beneficial use, 

 made necessary in putting that principle into practice. 



The doctrine of relation has, however, a much more important 

 bearing. It is necessary to the construction of large works, since 

 without it there would be no assurance that when such works are 

 completed there will be any wat^er left in the source of sup])ly. Other 

 ditches begun later might be rushed to completion and the water all 

 diverted, making whatever had been expended on the first ditch a 

 total loss. Witiiout this modification of the principle of beneficial 

 use it is doubtful whether any large canals would l)e built. Canals 

 are usually built to water land previously uninhabited: a company 

 building a large canal can not get settlers for all its lands at once. 

 This must necessarily be a slow process, taking in some cases many 

 years. Theoretically, the ai)plication of the water to land is neces- 

 sary to the acquirement of the right, and the question of what is 



