An Approach to Optimum Hydraulic Design of Diversion Weirs

A computer-assisted method is developed for the optimum hydraulic design of diversion weirs. With a number of relevant input parameters and a known design irrigation discharge, which can be estimated according to the project requirements of an irrigation field composed of a desired crop pattern, the overall dimensions of a diversion weir are determined. The program tests various combinations of dimensions for the structural elements, ie. intake, settling basin, spillway, energy dissipater, etc., within the recommended ranges of hydraulic requirements. The alternative with the desired hydraulic performance and having the minimum total cost is then proposed. The use of the program enables a designer to compare several alternatives in terms of hydraulic conformity, structural safety levels and cost. An application is presented to illustrate the capabilities of the program.