484 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



off and are subject to heavy summer floods when large quantities of 

 debris are carried into the main channels and deposited there. The 

 subsequent spring floods carry this material into the canals and 

 ditches or onto lands adjacent to the main channel. This problem 

 has become serious, especially in parts of Utah, and the division of 

 irrigation investigations, in cooperation with the Utah Experiment 

 Station, lias been instrumental in developing a remedy which 

 promises to control the menace at low expense to the threatened com- 

 munities. Under the direction of tlie department's representative 

 suitable small basins have been selected for the retention of the 

 gravel, and low crib dams of native timber, filled with rock, have 

 been built across their lower levels in order to check the flood waters 

 and permit the deposit of all the heavier and larger material. The 

 demonstration dams so far constructed have attracted much atten- 

 tion and have proved even more effective than was anticipated. 



3. A study of the efficiencies of the pumping plants in use in a 

 number of wells was made, and some study was also given to the 

 problem of developing ground water for irrigation purposes. 



In cooperation with the agricultural experiment station and with 

 the State engineer of New Mexico a study of the drainage conditions 

 in the central valleys of the Rio Grande which has been in progress 

 for several years was continued. Prior to the storage of water in the 

 Elephant Butte Dam, which was completed in 1916, a large percent- 

 age of silt was transported with the water of the Rio Grande and ap- 

 plied to the surface of irrigated lands. One of the effects of this was 

 to render the soil less pervious and decrease the losses due to deep 

 percolation. With the subsecj[uent use of stored water, containing 

 little or no silt, deep percolation resulting from irrigation increased 

 the percentage of waste water and caused a rapid rise in ground- 

 water levels. This condition was rendered more acute by the enlarge- 

 ment of channels, which increased seepage losses, and by the further 

 fact that much more water being available a more liberal amount was 

 applied. In 1917 about 64 per cent of the 90,000 acres in the Mesilla 

 Valley was water-logged to a greater or less degree. Other valleys 

 along the Rio Grande were also menaced by rising ground water, but 

 not to the same extent. This water-logging of improved lands con- 

 tinued to grow worse until 1919, when the Reclamation Service began 

 the construction of deep, open drains in the Mesilla Valley, which 

 soon became effective in lowering the ground water. 



It was for the purpose of rendering some assistance that this 

 bureau entered into the cooperative relations mentioned above. As 

 a result a large amount of data, obtained from test wells, has been 

 collected and tabulated. In 1921 a report on the drainage of 

 Mesilla Valley was published as Bulletin No. 129 of the New Mexico 

 Experiment Station. 



Since that time cooperative efforts have been occupied largely in 

 studying drainage conditions in the central valleys of the Rio Grande 

 in New Mexico in the hope that the landowners would unite and 

 organize a number of drainage districts. Field data on this project 

 were nearly completed during the past year, and preparation of 

 a report was begun. 



In cooperation with the Agricultural Experiment Station of New 

 Mexico, investigations pertaining to the use and duty of water were 

 continued during the year. In order to make the work more effec- 

 tive the investigations were conducted in cooperation with the 



