49 



uniformity or any gradual increase or decrease in the seepage re- 

 turns in any given section. The amount of water coming into the 

 stream from the hinds bordering it in any section must dei)end pri- 

 marily upon the amount of water received by these lands, either in 

 the form of rainfall or irrigation. The amoimt of rainfall varies 

 from year to year without any fixed law. and the amount used in 

 irrigation depends upon the amount which can be secured for that 

 purpose. In general, then, larger returns will be expected in wet 

 years than in dry years, since in such A^ears the lands receive more 

 Avater from both irrigation and rainfall. 



The rate of flow of water through soils is extremely slow, and water 

 applied to land at some distance from the stream takes several years 

 to reach the stream, so that the entire effect of heavy irrigation may 

 not be shown immediately in the return seepage. This would tend 

 to decrease the variations in the return flow due to wet and dry sea- 

 sons. It is therefore practically^ impossible to establish any relation 

 between the quantity of water received bj^ land and the amount of 

 water which will be supplied by this land to the stream. 



The measurements given in the table for each year were made by a 

 party which started at the canyon and Avent down the stream, the 

 supposition being that the rate of progress made by the party would 

 be about the same as the A^elocity of the flow of the river. In this 

 wav anv chano-es would be attributed to losses or gains in the channel 

 of the stream rather than to the rising and falling of the stream 

 as a Avhole. It is impossible to eliminate entirel}^ the effects of 

 increases and decreases in the flow of the stream as a whole, and to 

 the extent to which such fluctuations occur the value of these meas- 

 urements, as indexes of return seepage, is destroyed. Grouping these 

 measurements into periods will help to minimize the effect of varia- 

 tions since these Avill tend to offset each other. The measurements 

 given cover fourteen years. Dividing these into two seven-year 

 periods gives the results which are shown in the following table : 

 Gain or loss in flow of tiouili Platte Hirer by seccn-yeur periods. 



Section. 



Length. 



Before 1896. 



Total. Per mile. 



Miles. 



Platte Canyon to City ditch 5.25 



City Ditch to Littleton 6.25 



Littleton to Denver. 10.50 



Denver to Brighton -- 21.25 



Brighton to Platteville 16.00 



Platteville to Evans... IT. 00 



Evans to Putnam ditch - ^''^'^1 



Putnam Ditch to Fort Morgan 27.50 



Fort Morgan to Snyder. - i^"T 



Snyder to Merino ii'kn 



Merino to Sterling - - --- }*-5! 



Sterling to nifE - , 10-00 



nifE to Crook. I 15.00 



Crook to State line ■ o2. 50 



Sec-feet. 



28.15 



37.17 



56.95 



43.26 



67.94 



57.32 



119.90 



93.34 



25.12 



63. 35 



32.03 



16.58 



-14.83 



-21.25 



Sec-feet. 

 5.36 

 5.95 

 5.42 

 2.04 

 4.25 

 3. 37 

 4.36 

 3.39 

 2.18 

 3. .52 

 2.21 

 1.66 



- .99 



- .65 



After 1895. 



Total. Per mile. 



Sec-feet. 

 25.17 



27.:^4 



28.76 

 76. (i8 

 84. 49 

 99.5:^ 

 127.41 

 95.17 

 59.97 

 76.:«) 

 64.41 

 25.22 

 27.92 

 13.91 



Sec-feet. 

 4.79 



4.:« 



2.74 

 3.61 

 5.28 

 5.85 

 4.63 

 3.46 

 5.21 

 4.24 

 4.44 

 2.52 

 1.8(j 

 .43 



