Water System Design by Optimization: Colorado Springs Utilities Case Studies

Traditional water system master planning procedures have included designing water distribution networks to meet minimum system pressures, velocities and fire flow requirements. With the population of Colorado Springs projected to increase to nearly 520,000 by 2030, the Colorado Springs Utilities (Utility) has adopted “designby-optimization” to reduce costs and streamline design procedures. WinPipes is an EPANET-based water distribution system solver, optimizer, and output interpreter. It was modified for the specific requirements of the Utility. The optimization program was designed to evaluate multiple performance criteria for maximum and minimum pressure, maximum velocity, flow from a single hydrant, simultaneous flow from multiple hydrants, pump capacity and energy, and component failure based reliability. Development of the optimizer as well as the design-byoptimization approach of both a small and a large development is presented. The master planning of these developments represented unique challenges for the design and operation of the Utilities distribution system. Design-byoptimization allowed the Utility to meet specific design criteria at near minimum cost without compromising the integrity or reliability of the distribution system.