UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1026 
Contribution from the Bureau of Public Roads 
THOS. H. MACDONALD, Chief 
Washington, D. C. 
May 16, 1922 
IRRIGATION IN NORTHERN COLORADO. 
By Robekt G. Hemphill, Irrigation Engineer. 
CONTENTS. 
Page. 
Introduction 1 
Cache la Poudre Valley 2 
Meteorology 3 
Soils 5 
Water resources 6 
Seepage return 10 
Drainage conditions 12 
Exchange of water 12 
Page. 
Water rights 13 
Distribution from river 19 
Duty of the river 24 
Canal systems 26 
Gross duty for canals 42 
Farm irrigation 51 
Reservoirs 69 
Summary and conclusions 79 
INTRODUCTION. 
Prior to the establishment of the Union Colony at Greeley, Colo., 
in 1870, only a few primitive attempts at irrigation farming had been 
made along the route of the Overland Trail in that State. The 
small acreage of less than 1,000 acres which was then irrigated 
for the purpose of raising native hay, vegetables, and grain for the 
mining camps has increased in the half century which has since 
elapsed to over 3,000,000 acres, yielding an annual revenue at cur- 
rent prices of over $100,000,000. This great increase in acreage has 
carried with it a corresponding development in irrigation practice 
and in the customs and laws relating to irrigation. In fact, Colorado, 
while maintaining a ranking in irrigation development second only 
to that cf California, has established laws and customs and 
standarized practice to such an extent that the people of the State 
have become in many respects the leaders in such development 
throughout the Rocky Mountain region. In the aridity of its cli- 
mate, elevation above sea level, topography, soils, and crops Colorado 
bears a close resemblance to several neighboring mountain States. 
It is not surprising, therefore, to find that the methods of preparing 
land and applying water as well as the laws and administrative sys- 
tems of the State have been adopted by other States having somewhat 
similar physical conditions. The results of an irrigation investiga- 
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