EUKAL ENGINEERING. 187 



acres. The total power is 15,142 horsepower, of which 10,685 horsepower is 

 electrical and 4,457 horsepower is internal combustion or steam power. The 

 average power per plant is 9.1 horsepower, and the average area Irrigated for 

 each plant is 24.5 acres. 



Ground- water resources of the Niles cone and adjacent areas, California, 

 W. O. Clakk {U. 8. Oeol. Survey, Water-Supply Paper 345-H {1915), pp. IV -\- 

 127-168, pis. 9, figs. 16). — This report, prepared in cooperation with the de- 

 partment of engineering of the State of California, deals with the physiography, 

 geology, and ground-water resources of an intensively cultivated area of 20,800 

 acres in the Santa Clara Valley, Cal. 



" The ground water in the vicinity originates in the rain that falls upon the 

 drainage basins tributary to this part of the Santa Clara Valley and to a small 

 extent in the rain that falls upon the valley itself. The Niles-Irvington fault, 

 which cuts off the reentrant of the valley between Niles and Irvington, has a 

 profound effect on the surface drainage and on the circulation of the ground 

 water. ... It has also produced an underground dam which prevents the pas- 

 sage of ground water from the east to the west side of the fault except in small 

 amounts. . . . 



" The annual contribution of ground water to the Niles cone and the adja- 

 'cent area imder consideration west of the fault is believed to range between 

 2,600 and 59,000 acre-feet, or between somewhat wider limits, exclusive of the 

 withdrawals during the replenishing period. . . . The estimated annual require- 

 ment of ground water for irrigation of all crops now grown on the Niles cone 

 and on the adjacent area supplied by Alameda Creek west of the fault is 

 between 16,000 and 24,000 acre-feet, the smaller quantity being approximately 

 that now used for irrigation and the larger quantity that which will be 

 required in the future. . . . 



" The ground-water supply of the Niles cone and the adjacent area west of 

 the fault is little, if any, greater than the amount required by present develop- 

 ments and is hardly adequate for the full irrigation of the area and the present- 

 scale diversions by the Spring Valley and People's water companies. If further 

 diversions are necessary for public sui>plies of San Francisco or the transbay 

 cities, irrigation developments will probably have to be arrested imless provi- 

 sion can be made for conserving and utilizing tlie flood water which now runs 

 to waste. 



"The north end of the valley area east of the fault has a larger ground- 

 water supply in proportion to its extent than the area west of the fault. Its 

 supply is believed to be at least adequate for the irrigation of the arable land 

 that it contains, but the portion of this area from the vicinity of The Lagoon 

 southward is underlain by material that in general yields water too slowly for 

 irrigation. There is little danger, even with heavy pumping, that the area 

 under consideration will be seriously damaged by the encroachment of sea 

 water." 



Gazetteer of surface waters of Iowa, W. G. Hoyt and H. J. Ryan (U. S. 

 Geol. Survey, Water-Supply Paper 345~I (1915), pp. 169-221) .—This gazetteer 

 embraces descriptions of all the streams named on the best available maps 

 of Iowa. 



Surface water supply of Ohio River basin for the year ended September 

 30, 1913, A. H. HoRTON, W. E. Hall, and H. J. Jackson (U. S. Geol. Survey, 

 Water-Supply Paper 353 {1915), pp. 26^, pis. 5). — This report, prepared in coop- 

 eration with the State of West Virginia, presents the results of measurements 

 of flow made on streams in the Ohio Elver basin during 1913. 



Surface water supply of St. Lawrence River basin, 1913 {U. S. Oeol. Sur- 

 vey, Water-Supply Paper 354 {1915), pp. 136, pis. 2). — This report, prepared in 

 98262°— No. 2—15 7 



