The principal objective of this study was to optimize pump scheduling and reservoir releases in the Regional Municipality of Ottawa-Carleton's (RMOC) water supply system with a view to reducing hydro-related operating costs. Basically, hourly demands are to be met with minimum pumping costs. The preceding paper (part I) describes the RMOC system and the numerical model used in the optimization analysis. This paper (part II) presents the main results obtained from the optimization and also reports on the second study objective, which was to investigate the impacts on system operating costs of increasing (i) reservoir storage capacity, (ii) treatment plant capacity, and (iii) water demand by consumers. In general, linear programming was found to be a good modelling option for generating optimized pump schedules and service reservoir releases. The analyses of water management alternatives confirmed that RMOC's water supply system was designed for maximum day water demand; however, day-to-day operations would be facilitated if present storage and (or) treatment facilities were enlarged. Economically, it would be difficult to justify construction costs from the potential energy savings obtained from this study and therefore it seems important to start managing demand. Key words: water supply system, pump scheduling, pumping costs, optimization, modelling.
