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" :. O"'~~<' u_............... -x- perco1atio:J. losses from such land applications are exoessive. causing extensive areas. at present about 30.000 acres. to beoome water-logged or seeped. some of which lands have been injured. perhaps permanently. by concentrations of alkali. Some draina~ facilities at isolated locations had been con- structed prior to these investigatiolUl. Shortly before. a more general program of drainage was initiated. This work. involving the construo- tion of a system of open drain ditches of substantial depth. was con- tinued during the study period. - a factor neoessitating a oorreotion allo_nee for the annual effeots of drainage reoovery in the average year. At some future date. when drainage works are completed and ground water levels are stabilized. these investigations should be repeated. Briefly summarizing the results of the investigations of 1938- 1941. it appears that total inflows to the study area averaged 531.620 A. F'l total outflows averaged 3l.e .420 A. F.; and hence that the water resources were depleted 182.200 A. F. per average year. With a drainage correotion faotor of 13.000 A. F.. the annual depletion under pre-drainage conditions WaS plaoed at 195.200 A. F. in the average year of a period similar to 1938-1941. Results obtained for the average year of the study period are in suhstantial agreement with normal values. Average temper- atures were about normal. Average gross evaporation rates were about normal for the area. and sinoe average precipitation was slightly ahove. net evaporation rrtes were slightly below normal. On the other hand the average length of the growing seasons of frost-free periods. were lon~r. during the study period. than usual. Taking all pertinent factors into account. total depletions under pre-drainage oonditions were assigned a normal value of 193.560 A. F. annually. Undar the after-drainage con- ditions here assumed. normal depletions are estimated at 165.390 A. F. annually. Segregations of total water losses in n year of nonnal water supply and climatic conditions. and under the conditions before and after drainage. are shom in the following tablel .