50 



In some years the sections between measurements were not the same 

 as those given in the table, but inckuled two or more of the sections 

 as given. In such cases the gain or loss in the larger section is 

 divided between the sections as they are given in the table in propoi-- 

 tion to the mileage. The results given in the table are shown graph-' 

 ically in figure 3. In the figure the vertical scale represents gain in 

 cubic feet per second per mile, and the horizontal scale represents 

 distance from the upper measurements at Platte Canyon. The 

 hatched columns show the gains in the first seven-year period, from 

 1889 to 1895. Tlie solid columns show the gains in the second seven- 

 year period, from 1896 to 1903, excluding 1897. The difference in 

 the heights of the two columns for any section represents the increase 

 or decrease in the return waters for that section in the second seven- 

 vear period over the return waters for the same section for the first 

 seven-year period. The diagram shows that between Platte Canyon 

 and Denver the return seepage was greater for the first seven-year 

 period than for the second. This can be accounted for by the faci 

 that water formerly carried in open ditches and used for irrigation 

 in this section is noAV taken by the Denver Union Water Company 

 into its pipe lines and used in the city of Denver for domestic pur- 

 poses. In every section from Denver to the State line the gain in 

 the second seven-year period is greater than that in the first. The 

 smallest increase is in the sections from Evans to the Putnam ditch, 

 and from the Putnam ditch to Fort Morgan. The largest increase 

 is between Fort Morgan and Snyder, and the next largest between 

 Iliff and Crook. The small increase in gain between Evans and 

 Fort Morgan may be accounted for by the fact that along this part 

 of the river there have been constructed many ditches to collect 

 seepage water (PI. II). A large part of the seepage water which 

 would otherwise return to the stream is collected by these ditches 

 and used for irrigation, and hence does not show in the measurements. 

 The large increase in the sections beloAv Fort Morgan is doubtless 

 due to the fact that that part of the State is only now developing. 

 The last two sections, from Iliff to the State line, showed losses in 

 the first period and gains in the second period. The sands of the 

 river bed seem to be getting filled so that water flows in the surface 

 channels, where formerly it was all lost. Talcen as a whole, the 

 measurements give every reason to believe that the flow of the stream 

 in the lower reaches is increasing and will continue to do so. Up 

 to the present time there has been very little storage of water and 

 consequent irrigation in the late summer below the mouth of the 

 Cache la Poudre. During the year 1904 two large reservoirs were 

 constructed in this section, and plans for other reservoirs are being 

 made. The filling of these reservoirs will make possible the use of 



