I 



hi) 



DIVISION OF WATER KESOURCli:S ' 



26. ]>eeause of tlio seepape loss in the river channel beknv the i)oints 

 of diversion of the Consolidated Peoples Ditch, the remaininjr ditches 

 received water for .much shorter periods, ran<^ing from 36 to 225 days 

 each year. The avCrape .lenpth of run for these ditches was from 99 

 to 167 days, the average date of the end of the runs occurring between ; 

 June 21 and July 12. 



Practically all of the area served by gravity ditches in the Kaweah 

 River Delta receives supplemental water from ^n-ivate pumping plants. 

 Because of the low run-off of the river during the last decade there has 

 been a large increase in the number of plants and amount of power 

 used. There are no data showing the exact number of pumping plants 

 used to supplement gravity sup])lies. but records of the Southern Cali- 

 fornia Edison Comi^any. given in Table 51, .show the following increases 

 during the last five years within the exterior boundaries of the areas 

 served by the mutual water companies included in this study. These 

 figures do not include the Elk Bayou Area, which receives some water 

 from the Con.solidated Peoples Ditch, but depends upon pumping for 

 mo.st of its supply. 



TABLE 51 



EXTENT OF PRIVATE PUMPING ON AREAS SERVED BY SOME OF THE MUTUAL 

 WATER COMPANIES IN THE KAWEAH RIVER DELTA- 



' Records made available through the courtesy of C. H. Holley. These figures are for full sections within the 

 general areas served by the Consolidated Peoples (exclusive of the Elk Bayou Areal, Evans, Farmers, Flemming. Jen- 

 nings, Matiiews, .Modoc, Oakes, Persian, Uphill and Watson ditches. They are intended to show only the relative amount 

 of pumping and the increa.sc v/ithin the same area in a five-year period. The total area includc<l is 64, 640 acres, of which 

 28,655 acres were actually cropped and irrigated in 1929, according to crop surveys made by the Divbion of Water 

 Kesource.s, State Department of Public Works. 



= Estimated from power companies' records. 



» ila.sed upon available data regarding average depths to the water table, estimating average drawdowns and effi- 

 ciencies, r J J • 



• Based upon relationship between average size of plant and average amount of |)ower used and power rate in 

 accordance with Southern California Edison Company Agricultural Power Schedules P-4 and P-4 Optional. 



Table 51 indicates that there has been an increa.se of more than TOO 

 per cent in su])i)lem('ntal puMi])ing from 1924 to 1928. Partial records 

 for 1929 indicate a material increase over 1928. 



This enormous increase in pumping has resulted in a general lower- 

 ing of the water table of from 5 to 15 feet between 1924 and 1929 over 

 most of the area in the delta receiving gravity water from the above 

 mentioned ditches and a much greatei- lowering on areas not receiv- 

 ing gravity water. Before private pumping was very common, the 

 watet table stood within 5 to 10 feet from the ground surface in many 

 places.- Large areas depended entirely upon subirrigation. In some 

 places trees and vines were irrigated only occasionally by surface 

 application. Alfalfa was sometimes irrigated only once or twice dur- 

 ing a season. Since the lowering of the water table lielow the root zone, 

 these conditions liave changed and the annual siu'face applications have 

 increased. These increased applications are met largely by supple- 



