UNITED STATES DEPARTMENT OF AGRICULTURE 



1 BULLETIN No. 339 



-tcSJt^tJ.'— * Contribution from Office of Public Roads and Rural Engineering 

 ^Jp'^rSL LOGAN WALLER PAGE, Director 



Washington, D. C. 



PROFESSIONAL PAPER 



April 21, 1916 



EXPERIMENTS ON THE ECONOMICAL USE OF 

 IRRIGATION WATER IN IDAHO. 



By Don H. Bark, Irrigation Engineer. 



CONTENTS. 



Page. 



Introduction 



Plan of investigation 



Weather conditions in Idaho during the in- 

 vestigation 



Results obtained during 1910, 1911, 1912, and 

 1913 



Measurement of water used on farms and 



under complete canal systems 



Seepage investigation 



Survey of waste land in Idaho 



Proper duty of water for Idaho 



43 

 47 

 52 

 56 



INTRODUCTION. 



This bulletin contains the results of experiments made in coopera- 

 tion with the State Land Board of Idaho to determine the quantities 

 of water needed to produce the ordinary farm crops on the types of 

 soil common to that State. The experiments, in addition to investi- 

 gations strictly bearing on such irrigation requirements, included 

 certain supplementary investigations. 



The irrigation-requirement experiments extended from 1910 

 through 1913 and consisted in applying different quantities of water 

 to plots receiving similar treatment except for this factor. It is con- 

 sidered that these experiments fix within reasonable limits the 

 amount of water which must be delivered to fields to produce profit- 

 able crops under the conditions described. The supplementary 

 experiments were made for the purpose of determining how much 

 additional water must be allotted to cover waste and losses between 

 the point of diversion and the fields to be irrigated. 



The conclusions contain a discussion of the factors affecting irriga- 

 tion requirements in actual practice. 



Note. — The work on which this bulletin is based was done under a cooperative agreement between the 

 Office of Experiment Stations and the State Land Board of Idaho , several of the canal companies and the 

 railway companies operating in Idaho contributing to the expense of the work. The bulletin will be of 

 interest to officials administering the water supply of the Western States, to students of irrigation prac- 

 tice, and to farmers. 



13653°— Bull. 339—16 1 



