1917] KUBAL ENGINEERING. 485 



mac river basins in Massachusetts. A gazetteer of the streams of the State 

 is appended. 



Ground water in southeastern Nevada, E. Carpenter (U. S. Geol. Survey, 

 Watcr-tSnpply Paper 365 {1915), pp. 86, pis. 5, figs. 3).— This report deals with 

 the geograpliy, geology, and climate, and the occurrence, amount, distribution, 

 and quality of the ground water of an area of about 17,000 square miles in 

 soutlieastern Nevada, the topographic features of which consist " of a series 

 of parallel north-south mountain ranges and intervening broad debris-tilled 

 valleys." Analyses of 42 samples of the water showed that for domestic use 

 24 were good, 6 were fair, 8 were poor, 3 were bad, and 1 was unlit. For 

 irrigation use 31 were good, 5 were fair, and 6 were poor. 



The Navajo country: A geographic and hydrographic reconnaissance of 

 parts of Arizona, New Mexico, and Utah, 11. E. Gregory (U. S. Geol. Survey, 

 Water-supply Paper 380 (1916), pp. 219, pis. 29, figs. 29).— This report deals 

 with the geography, climate, and surface and ground waters of the Navajo and 

 Hopi Indian reservations in Arizona, New Mexico, and Utah, covering an area 

 of about 14,333,354 acres. 



" Bare rock constitutes a large proportion of the surface of the Navajo Reser- 

 vation outside the larger washes. ... As a whole the soil is, however, mainly 

 accumulated in the washes and along the smaller stream channels, where de- 

 posits exceeding 50 ft. in depth are not unusual." These alluvial deposits have 

 a composition almost wholly of sand and gravels. 



" By methods of flood irrigation the Navajo and Hopi together cultivate about 

 20,000 acres of land widely distributed over the reservation in fields about 3 

 acres in average size, rarely exceeding 200 acres. Considering the size of fields, 

 the nature of the soil, the fluctuating flow of streams, and the large amount of 

 debris carried in the flooded channels, this method of control by inexi)ensive 

 dams, rebuilt each season, is satisfactory, but the amount of water lost is 

 enormous." With reference to irrigation by storage, it was found that " the 

 storage grounds along the perennial streams of the Chuska Mountains and of 

 the Carrizo and Navajo mountains are at altitudes which prohil)it the cultiva- 

 tion of crops other than those which survive large ranges in daily temperature 

 and can endure frost at any month in the year. Water from reservoirs thus 

 located nmst be carried 10 to 30 miles before it can reach large tracts suitable 

 for general agriculture. In general the largest tracts of irrigable land are 

 farthest from permanent streams. The deeper canyons — Navajo, Piute, Laguna, 

 upper Moenkopi, Del Muerto, and others now occupied by streams — contain little 

 arable land. The construction of dams for storage of flood water in the wide 

 alluvium-filled washes presents engineering difficulties surmountable only at 

 prohibitive cost, a statement amply supported by a formidable catalogue of 

 failures. The amount of silt carried along the large valleys is sufficient to cause 

 embarrassment. . . . 



" The alluvial filling of washes and canyons is, in general, fine and coarse 

 sand rather than silt and clay ; the soil absorption and underground flow is 

 correspondingly large." " Tests were made of flood water taken from the larger 

 washes and allowed to settle from 12 to 3G hours. Eight such tests gave an 

 apparent percentage of sediment ranging from 6 to 25. One record of 34 per 

 cent was obtained, and a sample taken from a tributary of the Little Colorado 

 was found after 16 hours to have deposited nearly half its bulk." 



Special sections on domestic and stock water supplies are also included. An 

 extensive bibliography on the region is appended. 



Harney and Silver Creek projects, irrigation and drainage, J. T. Whistler 

 and J. H. Lewis (Oreg. Cooper. Work, Dept. Int. U. S. Reclamation Serv., 1916. 

 Feb., pp. 91, pis. 24). — This report, prepared in cooperation with the State of 



