OPTIMAL ESTIMATION OF STORAGE-RELEASE ALTERNATIVES FOR STORM-WATER DETENTION SYSTEMS

A heuristic optimization methodology is developed for obtaining the op timal allocation of storage capacity and release rate for the design o f storm-water detention facilities. The nonlinear optimization procedu re is formulated within the framework of production function theory. T he model is set up in terms of a nonlinear cost-objective function wit h a technological production constraint, which is the storage/release isoquant defining runoff volume or pollutant load trap efficiencies. T he process constraint is expressed as a function of the design variabl es of storage capacity arid release rate, in terms of runoff process s tatistical parameters and desired trap efficiency. The analytical stru cture of the model allows the use of marginal analysis in obtaining th e least cost solutions of storage capacity and release rate for any le vel of pollutant trap efficiency. It also allows prompt assessment of sensitivity, resiliency, and variability of pollutant loading rates. T he methodology is applied to a catchment in Minneapolis.