THE WATERS OF THE RIO GRANDE 
By WM. P. HEADDEN 
In Bulletin No. 82 of this station, “Colorado Irrigation Waters 
and Their Changes”, I dealt with the waters of the eastern slope, 
treating those of the Poudre Valley in greater detail than the rest, for 
four reasons, the principal one being that irrigation has been practiced 
on a larger scale in this valley than in any other section of the State. 
Irrigation was practiced on a small scale in the San Tuis Valley by 
the Mexicans earlier than by the settlers of the Poudre Valley, but 
this practice was by no means so extended as it has been in the Poudre 
Valley, from the time of its introduction. 
The second reason for confining our study largely to the waters 
used in the Poudre Valley was the fact that we are situated within 
this territory and all parts of it; the streams, ditches and\ reservoirs, 
are easily accessible at all times. These reasons were formulated in 
the bulletin referred to as follows : “The considerations which have led 
me to confine myself to the study of the Poudre River water to so great 
an extent as I have done, are evident. First, the water of the Poudre irri¬ 
gates, at the present time, as much if not more land than that of any other 
stream in the State. Second, it flows through our home valley, is easy of 
access, and we have fuller data and more intimate knowledge of it than 
of any other stream in the State. Third, irrigation has been practiced in 
this valley as long as in any other part of the State (a few sections where 
irrigation was practiced by the Mexicans expected), extending over a 
period of 43 years. Fourth, the oldest, and at the same time an extensive 
system of reservoirs, whose beginning dates back to 1875, has been made 
to supplement the summer flow of the river. 
t 
“Under these conditions the flow of the return waters has already 
been established, the first exaggerated effects of irrigating this land have 
passed away and the rate at which the return waters are carrying the soluble 
salts from the soil has presumably approached, if it has not already reached, 
the point at which it w T ill remain for years to come. The same may be 
assumed to be true in regard to the character of the salts taken into solution. 
“In this section, the period of drainage has begun, land having become 
valuable enough and water in such demand that drainage has already been 
instituted for the double purpose of preventing the land from being water¬ 
logged or seeped, and for rendering the water available for irrigating 
other land.” 
CHANGES IN WATERS OF EASTERN SLOPE 
These paragraphs were written thirteen years ago and are as 
applicable now as then. The work done preparatory to the publication 
of Bulletin No. 82 made the changes which take place in the amount 
