1917] RURAL ENGINEERING. 485 



" Fnll utilization of the ground-water supply for irrigation will not be eco- 

 nomically practicable until cheaper power or more valuable crops can be 

 introduced than are now in sight. Developments that may be practicable at 

 present are (1) the sinking of flowing wells of moderate depths in the re- 

 stricted areas where fairly copious flows can be obtained and the soil is not 

 irreclaimably alkaline; (2) the sinking of nonflowing wells and the installation 

 of pumping plants for raising high-priced crops or for raising ordinary crops 

 in localities where the conditions are exceptionally favorable or where the well 

 water can be used to supplement surface-water supplies. . . . Existing condi- 

 tions do not warrent the influx of a large number of settlers, nor of any without 

 means to sink wells and make other necessary improvements." 



The second part of this report deals with the geology and water resources 

 of Clayton Valley, an area of about 570 square miles in Esmeralda County, 

 Nev. 



" Most of the soil of Clayton Valley is too gravelly, sandy, or alkaline for 

 cultivation, but there is a small area, lying chiefly between the 50-ft. line and 

 the salt-grass boundary, that can apparently be classed as agricultural 

 soil. . . . The information available indicates that although water underlies 

 Clayton Valley in considerable quantities, it can not be successfully utilized 

 for irrigation because of its saline character and other unfavorable conditions." 



The third part of the report deals with the geology and water resources of 

 Alkali Spring Valley, an area of about 310 square miles lying almost entirely 

 in Esmeralda County, Nev. " The wells that have been sunk in Alkali Spring 

 Valley prove the existence of ground water in the valley fill. ... If 5 per 

 cent of the precipitation in the basin finds its way to the underground reservoir 

 the annual contributions amount to about 5,000 acre-ft. . . . 



" The valley fill of Alkali Spring Valley contains a supply of water that is of 

 fairly good quality for domestic and boiler use and for irrigation. Although 

 the quantity of water is not large, it is adequate for ordinary domestic, stock, 

 and industrial purposes, and would probably be adequate for a small amount 

 of irrigation. The valley contains considerable good soil, but the depth to the 

 water table is too great to make pumping for irrigation profitable under present 

 conditions except possibly for intensive market gardening." 



Ground water in San Simon Valley, Arizona and New Mexico, A. T. 

 ScHWENNESEN (17. S. Qeol. Survey, Water-Supply Paper 425-A {1911), pp. 35, 

 pis. S, figs. 2). — This report, prepared in cooperation with the Arizona Experi- 

 ment Station, deals with the geology, physiography, water supply, and agricul- 

 ture of an area 85 miles long and varying in width from 10 to 35 miles, which is 

 located in southeastern Arizona and the adjacent part of New Mexico. 



" Practically all the water in San Simon Valley is derived from the precipita- 

 tion on the drainage basin ; there is no considerable inflow of water from other 

 basing. In the San Simon and Bowie areas there are two distinct ground- 

 water horizons ; an upper horizon in the younger stream deposits and a lower or 

 artesian horizon in the deposits below the dense clay of the lake beds. In the 

 San Simon area the ground water of the upper horizon is less than 100 ft. 

 below the surface throughout a large tract extending along the axis of the 

 valley. The supply has proved ample for watering stock, for domestic needs, 

 and for the heavier demands of the railroad, and if it can be pnmned ecoriomi- 

 cally it is probably large enough for considerable irrigation. It Is doubtful 

 whether it would be profitable at present to pump this supply for irrigation. 

 In the Bowie region the supply at the upper ground-water horizon is very 

 scanty and it is generally necessary to sink to the lower horizon, even for 

 small supplies. 



