. Principles of irrigation engineering, arid lands, water supply, storage works, dams, canals, water rights and products. Fig. C.—Foundations for timber dam. Yakima Project, Fig. D.—Apron of partly finislied timber dam. Yakima Project, Wash. TIMBER DAMS 203 is sometimes used in order to increase the length of overflow anddecrease the depth of water on the crest. In this case there is atendency, however, to force the stream toward one bank, withconsequent danger of erosion, or if directed toward the intake ofthe canal, with liability of throwing the floods into the head andbringing in la
. Principles of irrigation engineering, arid lands, water supply, storage works, dams, canals, water rights and products. Fig. C.—Foundations for timber dam. Yakima Project, Fig. D.—Apron of partly finislied timber dam. Yakima Project, Wash. TIMBER DAMS 203 is sometimes used in order to increase the length of overflow anddecrease the depth of water on the crest. In this case there is atendency, however, to force the stream toward one bank, withconsequent danger of erosion, or if directed toward the intake ofthe canal, with liability of throwing the floods into the head andbringing in large quantities of sand, gravel and debris. A curved plan of timber dam has occasionally been used in orderto gain the advantage of the effect of the arch. The water pressureagainst the up-stream face putting the structure in gain in this respect is not very great, but is worthy of con-sideration if the abutments are sufficiently firm. Conditions of Stability.—Unlike a masonry, concrete or similarrigid structure, a timber dam is not dependent for stability on eachpart being held by friction or by the resistance due to cohesion of thevarious parts. On the
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectirrigat, bookyear1913
