THE IRRIGATION AGE. 



273 



ECONOMICAL HEIGHT WATEE MAY BE LIFTED. 



It is very unlikely that it will pay to pump water, 

 under present conditions in the valleys of the western 

 plains, to a total height of more than thirty feet, in- 

 cluding the suction lift of the pump. If the pump 

 lower the water in the wells ten feet; and if the dis- 

 tance to water be ten feet below the ground, and the 

 discharge pipe be brought into a reservoir or flume five 

 feet above the surface of the ground, the total lift 

 will be thirty feet, if five feet be added to cover loss of 

 head due to friction in suction and discharge pipe. 



STORAGE EESERVOIES. 



In order to irrigate economically from pumping 

 plants it is usually desirable to pump the water into 

 a reservoir having a capacity equal to the amount of 

 water the plant can furnish in six to eight hours. Such 

 a reservoir is absolutely necessary for best results with 

 small pumping plants. If the supply of water exceeds 

 500 gallons per minute it is possible to dispense with 



when the plant is not running as when running. The 

 rate of depreciation when idle will greatly exceed the 

 rate when running, if the machinery is neglected and 

 carelessly exposed. The charge for depreciation and re- 

 pairs should not be estimated at less than 10 per cent 

 of the first cost of the plant. 



APPROXIMATE COST OF FUEL REQUIRED TO PUMP 1,000 

 GALLONS OF WATER PER MINUTE FOR VARIOUS LIFTS. 



Feet. 

 10 ... 

 20 ... 

 30 .., 



oSJ 



Us 



Cents. 

 11.2 

 22.4 

 33.6 



S.-2 



jl! 



Cents. 

 14 

 28 

 42 



sSJ 



8 



Cents. 



4.2 



8.4 

 12.6 



2.b t i 



gs. c s 

 IHI 



I2JS3, 



Cents. 



6 



12 

 18 



Dollars. 



70 

 140 

 210 



NOTE. 1,000 gallons of water per minute pumped continuously for 

 eleven hours is equivalent to two acre feet of water. 



The Famous Clearwater Country, Idaho. Northern Pacific Railway. 



the reservoir, especially if the supply greatly exceeds this 

 amount. Plants furnishing over 1,000 gallons per min- 

 ute can usually be best operated without the use of a 

 reservoir. 



COST OF PUMPING. 



The cost of recovering ground water from wells is 

 made up of four principal items: (1) fuel and sup- 

 plies; (2) labor; (3) depreciation and repairs; (4) 

 interest on the first cost of the plant, or on the capital 

 invested. The first and third of these items are par- 

 tially under the control of the owner of the plant. If 

 the installation is carefully designed and its parts well 

 proportioned, the cost of fuel can be kept at a mini- 

 mum; and similarly, the charge for depreciation and 

 repairs will be kept low if good machinery be purchased 

 in the first place, and careful attention be given to its 

 maintenance when in operation and when idle. The 

 charge for depreciation will be as great, if not greater, 



The accompanying table gives an estimate' of ap- 

 proximate cost for fuel and maintenance of a pumping 

 plant having a capacity of 1,000 gallons of water per 

 minute for total lifts of ten, twenty and thirty feet. 



In order to determine approximately the cost of 

 pumping water any distance between twenty and thirty 

 feet, a proportional part of the cost for ten feet can be 

 added to the cost for twenty feet. Thus, to get the cost 

 of pumping water a distance of twenty-five feet, half of 

 the numbers in the first line of the table can be added 

 to those in the second line. The table should only be 

 used for estimating the cost of pumping water for lifts 

 lying between twenty and thirty feet. The cost for ten 

 feet is given for the purpose of making estimates, but' 

 it should not be supposed that the cost for this low lift 

 would be merely half of that for the twenty-foot lift, 

 as frictional losses and others would tend to make the 

 cost for the low lift higher than that stated in the table. 



