Optimal allocation of water withdrawals in a river basin

An increasing number of states use permit programs to coordinate and to control water resource allocations. A general approach is suggested for allocating and permitting water withdrawals in a river basin. A mathematical programming methodology facilitates optimal streamflow allocation while maintaining desired levels of instream flow. The approach uses a graphical tool, the flow duration curve, to illustrate the quantity and frequency of joint streamflow withdrawals in a river basin. The methodology is unique because while it uses mathematical programming methods, it is implemented using a spreadsheet optimization tool, Microsoft Excel Solver, and the solution is illustrated in a graphical form so that nontechnical individuals can easily understand the methodology results. The ability to apply the methodology and clearly explain the results is extremely important since many nontechnical individuals are involved as policymakers in water allocation decisions.