Side Channel Spillways: Hydraulic Theory, Economic Factors, and Experimental Determination of Losses

The design of a side channel spillway involves certain special hydraulic and economic factors which, it is thought, have not been previously discussed. On account of the disturbed conditions of flow, there are large internal frictional losses, the relative amounts of which are largely dependent on the magnitude and form of the individual installations. Flow can be computed by Bernoulli's theorem, using an experimentally determined coefficient of loss, similar to that of friction in ordinary flow, but such a coefficient would not be constant, and would need to be determined separately for many different sets of conditions. This situation can be avoided by utilizing the law of conservation of linear momentum for determining the flow. Formulas required for this purpose are developed.