. Principles of irrigation engineering, arid lands, water supply, storage works, dams, canals, water rights and products. Fig. $3.—Balanced valve for regulating reservoir discharge under high dam, Wyoming. Fishways.—Where diversion dams are placed in perennial streams,it is usually required by state law that some form of fishway orladder be built so as to permit the fish to pass the essential features are an inclined way on the slope of aboutone in four, provided with compartments making a series of boxes OUTLET WORKS 257. T3 > 5 o T3 ?a -^W<-*-4-if4 258
. Principles of irrigation engineering, arid lands, water supply, storage works, dams, canals, water rights and products. Fig. $3.—Balanced valve for regulating reservoir discharge under high dam, Wyoming. Fishways.—Where diversion dams are placed in perennial streams,it is usually required by state law that some form of fishway orladder be built so as to permit the fish to pass the essential features are an inclined way on the slope of aboutone in four, provided with compartments making a series of boxes OUTLET WORKS 257. T3 > 5 o T3 ?a -^W<-*-4-if4 258 PRINCIPLES OF IRRIGATION ENGINEERING open at the top. From the top down each is successively lower,the water flowing from the higher into the lower down this slope. A supply of water of at least 5 cu. ft. per second is usually neces-sary to operate a fish ladder of this character. The water may beallowed to spiU over the edges from one box or compartment tothe next and also a portion may flow through a small rectangularopening in the lower corner of each compartment. These openingsare not placed in line with each other, but occupy successive alternatelower corners of the partitions, so that the water entering onecompartment seeks the lower corner where it escapes through theopening usually 8 in. high by 12 in. wide. It then flows diagonallyacross the next compartment to the lower corner and so on, therebeing formed a succession of pools in which the fish can rest, andthen dart through the submerged opening or they may leap overthe crest into the
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectirrigat, bookyear1913
