An Excel-Based Decision Support Tool for Water Use Efficiency Optimization

A new Microsoft Excel-based Water Use Efficiency Optimizer Tool has been developed by Malcolm Pirnie to assess various water use efficiency measures for developing water conservation strategy and priorities and for comparisons with economics of other water resource options. The Decision-Supporting Optimizer Tool assists in water resources planning decision making at both regional and individual utility levels. The Water Use Efficiency Optimizer assesses a mix of water resources planning options for managing demands and supplies within the primary constraints of minimizing costs while meeting specific water supply and water conservation goals. The tool uses Excel's “Solver” feature (which is an “add-in”) as a platform. The solver tool uses concepts of linear programming to provide an optimal mix of water resource options that can achieve goals within different types of constraints, including resource capital and operational costs, available budget, water savings, available minimum and maximum opportunities to implement options, resource option characteristics, and others. The tool enables users to model different water resources planning options to determine the most optimal scenario in consideration of prescribed user constraints and utility/regional service area characteristics. This paper describes the concepts and components of the tool, input data needs, assumptions and constraints, areas of applicability, and specific case studies for individual utility and regional water use efficiency planning.