Akizoxa A(.Kicri/rLRAr< Iv\im;kimi;\ r Statkin 479 



It is not considered feasible to continue the heading of the St. 

 David canal in its present location, Ijecause of the rapidly increasing 

 width of the river channel. The heading should be in the rock 

 gorge about two miles north of Fairbank. Three alternative loca- 

 tions were selected in the rock gorge, and surveys and test borings 

 have been made to determine the best site. Three test holes have 

 been drilled to depths of 41, 79, and 52 feet without reaching bed- 

 rock. The best location is opposite the isolated rock island near 

 the north end of the gorge. A diversion dam of the weir type is 

 now being designed. 



SULPHUR SPRING VALLEY 



Gaging stations were installed August 1, 191'', at the mouths 

 of Rucker, West Turke\ . and Rock creeks, and in ]\Iarch, 1920, 

 at the mouth of Post Creek. These stations and one on the Wiiile- 

 water at Douglas are being maintained. 



Seepage losses on the creeks were measured to determini.- tlic 

 principal areas of recharge. 



A project for a diversion dam on the Whitewater ai)out 18 

 miles north of Douglas was surveyed and designed. This site is 

 the present head of deep river cutting. The purpose of the dam 

 is three-fold, — to permit the diversion of flood flows, to preserve 

 the excellent grass pastures above the dam which will be under- 

 drained if the headward erosion continues, and to forestall the 

 necessity for many bridges on the main creek and its tributaries. 



YUMA MEvSA EXPEROn< NT STATION PUMPING PLANT 

 The pumping plant and pipe line, the design of which was 

 noted in the last annual report, was installed in May, 1920. It 

 has provided the water supply for the citrus groves throughout the 

 summer. The plant is of the most reliable type possible for irriga- 

 tion service. The rates for power, however, are high and the cost 

 of the power for pumping for the irrigation season of 1920 has 

 been almost $50 per acre. 



THE CHIPPEWA PUMP 

 A Chippewa double-acting deep-well pumj) of small size was 

 tested in the irrigation laboratory. The high eftlciency that was 

 expected was not found, but nevertheless the pump should be good 

 for many situations, particularly stock-watering Avells of small 

 diameter. 



