372 IRRIGATION INVESTIGATIONS IN CALIFORNIA. 



$10.49 per acre-foot of water delivered. This does not cover interest on cost of 

 plant. The area irrigated was 125 acres, planted to citrus fruit trees, and Mr. R. C. 

 Allen, manager of the company, states that the trees were given more water per acre 

 than the}' had ev^er before received, even whenthe Sweetwater Reservoir was full. 



The fine texture of the sand surrounding the pumping plant at Linwood Grove 

 proved a serious bar to the development of water, as the passage of water through 

 the sand was extremety slow, and the 7t) wells were unable to yield as much as the 

 pumps provided could lift. It became desirable and necessarj', therefore, to provide 

 more water to keep the pumps properly occupied, and an auxiliary plant was put in 

 3,000 feet higher up the valle,y. Here the development consists of forty 2-inch wells, 

 reaching to a depth of 50 feet from the surface, the suction pipe connecting with all 

 the wells being laid in a trench excavated from 10 to 15 feet in depth. The wells are 

 arranged in pairs along the suction pipe, which is about 1,000 feet in length, and are 

 spaced 50 feet apart, lengthwise of the pipe. The parallel row of wells, 30 feet from 

 the suction i)ipe, is reached bj' branch suction pipes, 2 inches in diameter, lying in 

 trenches cut at right angles to the main, which is 8 inches in diameter. These wells 

 are thus all coupled together and connected to a 5-inch centrifugal Krogh pump, 

 driven by a 22-horsepower gasoline engine, which lifts the water about 30 feet, 

 including suction, and delivers it to a 12-inch pipe, lying on the surface, by which 

 the water is convej'ed by gravity- to the Linwood plant, where it is lifted again and 

 forced into the mains against a head of about 140 feet. This plant develops about 

 75 miner's inches, and was particularly useful last j'ear, in the fall, when the other 

 plants were beginning to give down somewhat in their 3'ield. It has been entirely 

 reconstructed this year, and the suction pipe lowered to the depths mentioned. 



With the resumption of the obligation to continue pumping an irrigation supply 

 throughout the irrigation season of 1900 came the necessit}' of more thoroughly 

 exploiting the subterranean reservoir of the Lower Sweetwater Valley, between the 

 dam and the mouth of the river. A plant was erected and installed April 29, 1900, 

 at Bonita, where 42 wells were sunk to a uniform depth of 50 feet below the surface. 

 These are 2-inch wells, arranged after the plan of the Linwood auxiliary plant, in 

 pairs every 50 feet on the line of the suction main. One of each pair is at the 

 main and the other 30 feet distant, at right angles. The suction pipe is placed in a 

 trench from 5 to 8 feet beneath the surface. This plant differs from the others in 

 that it has two 6-inch centrifugal pumps in tandem, pumping the water to and 

 through the 30-inch main pipe against a force and suction head of 140 feet. In May 

 the water not directly used was being forced back through the Sweetwater Dam, the 

 gate being left wide open, into the reservoir, where it was being stored for use a 

 little later on. The pump nearest the suction is driven by a 22-horsepower Fairbanks 

 & Morse gasoline engine while the other pump is actuated by the same class of 

 engine, having 28 ho)sepower. The water developed at this point with the plant 

 described was about 74 miner's inches. 



One or two additional plants will probably be erected and installed before the 

 irrigation season is over. A deep test well is being bored at National avenue, and 

 tests are being made at other points. Additional wells are also being bored at the 

 Sunnyside plant. 



