Optimization Model for the Design of Infiltration Basins

A nonlinear programming (NLP) optimization model has been developed for the minimum cost design of infiltration basins and infiltration trenches. The focus of this optimization model and approach is to provide a functional and versatile tool to simultaneously determine the peak inflow and runoff from a design storm event based on watershed parameters, and to optimize the size of an infiltration basin based on the design storm parameters, infiltration characteristics, basin capacity, and mounding. Two optimization models are developed, one is based upon the rational method and the second is based upon the modified rational method. Both approaches use the Green-Ampt method for infiltration, in addition to a method for defining the mounding effects. The various hydrologic concepts are defined through constraints in the optimization models. No previous optimizations models for infiltration basin design have been developed that can accomplish the detail of this new model. The nonlinear programming model is solved using the GAMS (General Algebraic Modeling system) software which is readily available.