Operational planning and control of urban water distribution systems

A water distribution system consists of several sources of water supplying points of demand through a transmission and distribution system consisting of a network of pipes, pumps, elevated storage reservoirs, and filter plants. In recent times, operational planning and control of urban water distribution systems is causing concern to utilities because of three important considerations. First, with the increase in size and complexity of the system, large capital investments are required for expansion of the system. Secondly, as a result of increasing power costs, water utilities have to pay high costs for pumping water. Finally, environmental constraints have contributed to difficulties in locating additional elevated storage facilities that would be required to serve the increase in demand. The overall consequence of these factors is the need for improving storage management and pump operating strategies so that operating costs will be reduced without sacrificing the level of service to consumers. This has led some utilities to install computers to improve system operation by performing data logging, alarm monitoring, report generation and supervisory control functions. Operator experience has provided the guidelines necessary to develop computer logic and to initiate control action through set points on levels, pressures and flow rates in the system.