Show measurement MEASURE MEN A 0 DUTY OF WATER by don H bark U S engineer in in charge of irrigation investigation in idaho oregon short line railroad december 1912 demonstration train tho the gi licater cater part of 0 the land la in the west would be practically worthless without water ater with which to irrigates irrigate it yet there is far less attention given alvea to tho the measurement ot of this water than there Is to the measurement ot of the land under the C carey arey act tho the land is sold sod to the settler for SO LA cents per acre and woud oud hardly bo be worth that without the tl 0 o water while water costs ibe settler all tho the way from frolin 25 to per acre so no one would think of buying a larm farm or any piece ot of property arty without having its boundaries located by the county surveyor or a competent engineer yet nine out of ton ten irrigators accept tho the water that is given them by the water m master a ster with out measurement or question ever even though it Is fa tea fm times as valuable as the ille land to which it la Is applied these chese condit conditions lous should be changed every irrigator should install a measuring device in his head ditch and learn how to measure water accurately and then see that he secures whatever water he be is entitled to we have been aerl far too careless in fit the past about water measurement ur hl miners iners inch water A vas as first used in idaho and other western states lor for mining purposes tile common method of meas brement being called the miners inch method the miners inch was the unit upon which such measurement i was based being the amount of water that would flow through ai a sharp edge orifice one inch square under a given Pres pressure surL the quantity called for by inch however varied in different stat s due to the fact that the pressure oer the orifice was not tho the same the idaho statute called tor for a pressure ot of 4 inches over the center of the orifice while in liontina SIon lion tana the law called lor for a 6 inch pressure this variation resulted in ia no end of confusion and as the miners inch was not adapted to tile the measurement of I 1 largo large streams its uso use has been discontinued lor for the cubic toot foot per second the cubic foot per second which represents a definite tangible amount yat that is easily understood was adopt fd f as the legal standard for the atio ni oas ment of water by the idaho legislature EA aks i in it is commonly known own as the second foot and rep represents the flow of water will exactly fill a vessel containing one cubic foot each second of time tor for is as long a period as it is allowed to flow if hence ence a flow of 0 ono one cuble foot per second delivers CO 60 cubic feet per minute or 3 GOO cubic foot feet per hour or cubic teet feet in ia a day of 24 hours it is found that one cubic foot per second equals a flow of almost exactly 50 idaho miners inches or gallons per minute A flume one foot wide and one inq foot deep if filled with water that is flowing at the rate of exactly one foot per second will carry one cubic loot tier per second and other flum es or ditches in the same proportion the quantity discharged depends upon both tho the velocity elo city ot of the flow and the area of 0 cross section of the advancing stream ot of water these two factors are AX taken into consideration when nhen determining ter mining the flow of of large streams and canals it being ony only necessary to de the area of tho the cross section and the average velocity which two amounts multiplied together gives tho the discharge the cross section is found by multiplying tho the average depth dc ath of the stream by the width the average velocity Is found by measuring the rate of the same either with floats or with a current meter especially constructed for the purpose A close approximation of tho the velocity can be secured ty by noting the am time a that I 1 Is required for a surface float to advance through til rough or more feet 0 of tho the ditch this gives the surface velocity and to III find ai d tho the average velocity one must multiply tho the surface velocity b by 7 8 since sinca the average velocity is that macii much slower than tho surface velocity owing to the friction on the sides and aad bottom of tho the channel while the above mentioned methods are those used by engineers and others tor for the measurement of large canals and rivers this method is not adapted to tho the continuous measurement of small streams and il ditches itches because of 0 the time involved arld and the liability for error where tho the measurements are not carefully made acre foot where large volumes of 0 water are arc to be considered the expression of the amount in cubic feet would involve the use of such large numbers that the same would bo be cumbersome in order to simplify these expressions tho the term acre toot is used which represents enough water to cover an acre one foot in depth or cubic feet feel the use of this term has the additional advantage of being compared with tho the acreage as for example a reservoir containing acre feet of water would furnish a depth of 2 feet tor for acres of land A cubic foot of water per second flowing continuously tor for 24 hours furnishes almost exactly two tio aero acro feet of water |