15 



available. Therefore, the table is not to be taken as exact, but it 

 gives a general idea of the average available water supply for the 

 lands in the South Platte Valley. The average total supply for the 

 period from April to September, inclusive, is •2J('u) cubic feet per 

 second. Against this supply, rights" aggregating 30,507.47 cubic 

 feet per second have been recognized by public; authorities in Colorado 

 and Nebraska. (See p. 89.) That is, the rights to be sui)plied l)y 

 this river system are more than ten times as great as the average flow 

 of the streams. This statement of averages does not, however, give 

 a correct idea of the relation between Avater supply and water rights. 

 Many canals were built with the full understanding that water could 

 be obtained only at intervals, and the frequency and duration of 

 floods are of more importance to their owners than average flows. 

 The conditions are more correctly represented by the tables given 

 below, showing the maximum, minimum, and mean discharges of the 

 South Platte at Deansbury and of the Cache la Poudre above P'ort 

 Collins, with the differences between these discharges and the sum of 

 nil decreed rights to water. 



The table which follows gives the maximum, mean, and minimum 

 flows of the South Platte at Deansbury, Platte Canyon, or South 

 Platte for the years 1890-189-2 and 189G-1903. The maximum for 

 each month is the greatest discharge reported for that month during 

 the period covered, rather than the mean maximum. The minimum 

 is obtained in the same way. The sum of the decreed rights to water 

 from the South Platte between the point of measurement and Denver 

 is approximately 1,913 cubic feet per second. The differences be- 

 tween this volume and the discharges of the stream are shown in the 

 last column of the table. 



a Rights to water are theoretically based on use. jukI no one has a riirht to 

 more water than he has put to use. However, the courts have decreed to some 

 parties rights to more water than they have used and more than their ditches can 

 carry. On the iiasis of the dec-rees the parties have these rights, while on the 

 basis of the theory the rights do not exist. The figures given here are based 

 on the decrees. (See pp. 2G-39.) 

 30437— No. 1.57—05 M 2 



