UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1340 
Washington, D. C. 
October, 1925 
IRRIGATION REQUIREMENTS OF THE ARABLE LANDS OF THE 
GREAT BASIN 
By Samuel Foettek. Associate Chief of the Division of Agricultural 
Engineering, Bureau of Public Roads 
CONTEXTS 
Page 
Introduction 1 
l nits and forms of expression 3 
The Great Basin 4 
General character of the soils of the 
Great Basin 5 
Climatic conditions 6 
Water supply 6 
Agricultural products 12 
The relation of irrigation water to 
crop production. 13 
Page 
Time of irrigation 19 
Conditions influencing the quantity 
of water required for irrigation 29 
Water requirements as affected by 
State, community, and corporate 
regulations 33 
Lands to be reclaimed 37 
Seasonal net water requirements 3"S 
Use of water on crops in the Great 
Basin 39 
INTRODUCTION 
The irrigation requirement of arable land, or, as it is frequently 
termed, the " duty of water " in irrigation, may be said to be the 
yardstick by which the utility of the diverted waters of western 
streams and the agricultural prosperity of the arid region are meas- 
ured. This subject pervades irrigation in all its phases. It has to 
do with the legal phase in the definition and settlement of water 
rights: with the administrative phase in the equitable apportion- 
ment of public water supplies : with the engineering phase in deter- 
mining the capacities of canals, pumps, reservoirs, and irrigation 
works in general; with the economic phase in the prevention of 
waste and the attainment of the highest possible efficiency : with the 
financial phase in determining the permissible cost of reclamation 
that can safely be undertaken with a known water supply, and with 
the agricultural phase in maintaining and controlling soil moisture 
in such a way as to produce profitable yields of crops. 1 
In most irrigated sections there was an abundance of water for 
irrigation for several decades after irrigation was begun. This 
1 Duty of Water in Irrigation, by Samuel Fortier. 
Engineering Congress, 1915, vol. 2, p. 45S. 
Proceedings of the International 
