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. . approximately six months and will be based entirely on currently avail- able data and the report may include suggestions regarding data needed in long-time study. Mr. R. G. Andrews, Hydraulic Engineer of the Soil Conservation Service at Fort Worth, estimates that the study will begin in May, d, San Simon Basin Study In the watershed of San Simon Creek, a tributary of the Gila River in Arizona, a study is proposed for evaluation of the effects of detention reservoirs on the flow downstream. Two such reservoirs of 3,500 and 2,uOO acre-feet capacity have been constructed on public lands administered by the Bureau of Land Management and others are proposed; of which one would have 27,000 acre-feet detention capacity. Downstream is Coolidge Dam which imoounds waters of the Gila for the San Carlos Irrigation District and the District officialB have protested the con- struction of detention res,rvoirs by the Bureau of Land Management, claiming that inflow to its reservoir is depleted thereby, The study program is still in the negotiation stage. e. Other Studies Mr. H. G. Bobst, State Conservationist of Nebraska, reported that they have some sub-watershods in the U"pc;r Salt (pilot) projects instrumented which, in a few years, should ~ive some information re- garding the effectiveness of land treatment and det8ntJ.on reservoirs, He also said that the Agricultural Research S,rvic~~ Hydrologic Investigation Station at Hastings, Nebraska, has SO;)le information on two watersheds - one treated and one untreated - but Ghat neither of the watersheds had detention reservoirs. An inquiry directed to Mr. L. L. Kelly, who is at the Agricultural Research Service office at Hastings, Nebr., brought the following reply: "The Agricultural Research Service is interested in the effects that upstream nrograms may have on downstream water yield and is doing som8 work on it. "First, W3 are about to get under way in analysing all available data to determine the dependable flows from small watersheds. This study will be pointed toward the need of agricultural agencies for design data for small water supply structures from the size of :'\ stock wat:or pond to that of a small municipal structure or irrigntion facility of perhaps well under a hundred square miles drainage area. In this study we will invC?stigate possible difforenC8s in runoff from treated and untreated areas. We hope th~t the investigation will result in a set of fre~'ency curves for cnch signific~t physiographic area, and which will reflect ,liffer,)nces in size - 11 _.