REPORT OF THE SECRETARY OF AGRICULTURE. LXXXYTT 



canals. The water .supi)ly in the same river gains in some places from 

 seepage and loses in other places. An illustration of the change in 

 volume due to this action was shown last season by Snake Riv6r, in 

 Idaho. At one place in its course it carried enough water for 200,000 

 acres of land. Fort}^ miles above it was dry. Nothing had been added 

 to it b}" surface streams in the intervening distance. Where it was dry 

 the water had sunk into the sand; farther down it reappeared on the 

 surface. 



The studies of evaporation and seepage have been extended in order 

 to show more clearly the extent of the iosses from canals from these 

 sources. Much interest is being manifested in these investigations by 

 managers of canals. Definite information on the subject is needed by 

 those who are planning new works and to enable the managers of the 

 old ones to distribute their water supply to the best advantage. 



The operation of canals w' hich divert streams flowing over sand}^ 

 beds, or which are heavily charged with silt, has proven a source of 

 great perplexit}' to those in charge, and the influence of sediment in 

 the maintenance of reservoirs deserves careful consideration in the 

 location of these works. Much valuable information on this subject 

 has been gathered during the past year. 



In some of the older irrigated districts the percolation of water from 

 canals, or its wasteful use on fields, has created bogs and marshes on 

 the lower lands. To make these over-watered fields again productive 

 drainage will have to supplement irrigation. The plans for drainage 

 should be made, like those for the original watering, on a comprehen- 

 sive plan. The individual irrigator can not drain his own farm with- 

 out the cooperation of his neighbors. Plans for effective cooperation 

 are needed, and the aid of this investigation has been asked in their 

 preparation. 



IRRIGATION IN HUMID SECTIONS. 



Interest in irrigation in the humid regions of the United States is 

 constantly growing. This has been stimulated throughout the Middle 

 West b}' the drought of last summer, and in the South and Southwest 

 by the success of the rice industry. In the State of Louisiana more 

 miles of irrigation canals have been built and more mone}^ expended 

 on ])umping plants during the past two years than in any arid State. 

 The application of irrigation in growing rice in Louisiana and Texas 

 has made land worth originally from $5 to $10 per acre worth |50 to 

 $iO(J per acre, and promises to enable the United States to become an 

 exporter instead of an importer of this important food product. 



A recognition of the increased interest in irrigation in the East has 

 caused this Department to extend its investigations in this part of the 

 country. The experiments being made by Prof. R. C. Waters, of 

 the Agricultural Experiment Station of Columbia, Mo., are attracting 



