EURAL ENGINEERING. 881 



This report deals with cooperative worlc by the U. S. Reclamation Service and 

 the State of Oregon, the purpose of which was to provide detailed surveys and 

 investigations of the water resources of the State, with particular reference to 

 irrigation and power possibilities. The report deals only with the upper Des- 

 chutes River basin. 



The normal summer minimum flow of the Deschutes River at Bend is ap- 

 proximately 1,600 second-feet. The mean annual run-off at Benham Falls for 

 a period of ten years is 1,210,000 acre-feet, of which approximately 20 per cent 

 is from Crane Prairie. The area now irrigated, or to be irrigated under the 

 Carey Act, north of Benham Falls is approximately 115,000 acres, for which 

 there is available from the summer flow of the Deschutes River, without stor- 

 age, not to exceed 450,000 acre-feet of water. In addition it is proposed to 

 irrigate under the Carey Act about 30,000 acres of land south of Benham Falls 

 for which storage is planned in Crescent Lake. It is stated that full irriga- 

 tion development in this basin will require storage of the greater part of the 

 entire remaining supply of over 750,000 acre-feet. Further irrigable areas 

 considered in this investigation are a west side unit of approximately 20,000 

 acres north of the present State Tumalo project, with an alternative area of 

 approximately 15,000 acres; a north unit of approximately 100,000 acres east 

 of Deschutes River and north of Crooked River ; a south unit of approximately 

 48,000 acres south of the present Central Oregon canal and extending north 

 to Powell Buttes ; and an east side unit of 35,000 acres, consisting of the north 

 canal unit of the Central Oregon Irrigation Company. 



The duty of water is estimated at from 2 to 21 acre-feet per acre at the land, 

 and the irrigation season has been estimated to be from early May to early 

 September, with a maximum use of water during July. Storage is proposed 

 of approximately 100,000 acre-feet in Crane Prairie and 400,000 acre-feet in 

 Benham Falls reservoir. 



A survey of the soils of the irrigable areas showed them to be generally 16 in. 

 or more in depth. Their physical character with reference to irrigation and 

 cultivation is generally good, but it is stated that their plant food content, 

 particularly with reference to nitrogen, is frequently small. It is estimated 

 that the water supply is adequate for the irrigable areas in question. 



It is stated in conclusion that there is a fall in the river between 

 Benham Falls and Bend of nearly 400 ft. available for power develop- 

 ment in four separate falls of from 65 to 110 ft. each ; that with the domestic 

 water supply of 330 second-feet estimated, it is feasible to develop at these 

 falls 20,000 horsepower continuously throughout the year, with a load factor 

 of 50 per cent ; and that with the full irrigation development it will be possible 

 to develop approximately 100,000 horsepower, limited to the period of the 

 irrigating season. 



A number of maps and charts accompany the report. 



Memorandum on the geology of the ground waters of the island of 

 Antigua, British V/est Indies, T. W. Vaughan (West Indian Bui, H (WW, 

 No. 4, pp. 276-2119). — The geology of the island with reference to the ground- 

 water resources is outlined, and it is concluded that the geologic conditions do 

 not satisfy the requisites for procuring an artesian water supply. It is stated 

 that the only water-bearing formation of importance is the limestone of the 

 limestone district. " The development of an adequate supply may be expected 

 from three sources, viz, (1) shallow wells in the limestone district, (2) shal- 

 low wells in the alluvial fillings along stream ways and at the foot of talus 

 slopes in the southwest volcanic district, [and] (3) impounding water, espe- 

 cially in the volcanic district, where it appears there are valleys adapted for 

 damming." 



