TABLE OF CONTENTS A water supply system includes the water supply, treatment facilities, pumping facilities, transmission lines, and local distribution network. The distribution network consists of pipes, fittings, valves, and other appurtenances designed to convey potable water at adequate pressures and discharges. Adequate discharges are necessary to cover the range of flows due to the fluctuation in demand. Adequate pressures are necessary for firefighting, general service to residents, and economic considerations such as leakage and energy losses. The pressures within a water supply system must be high enough to overcome the energy losses in the system, yet maintained below the point at which damage to fittings and other appurtenances occurs. Due to the size and varying topography within many systems, different pressure zones may be generated to ensure reliability in meeting the fluctuation in demands. These pressure zones are typically divided through booster pumping stations and storage facilities. Pressures and discharges are a function of the hydraulic characteristics of the system as well as the system's service characteristics. Service characteristics include such items as demand as it relates to present and projected population, economic base, fire flow, and climate. Hydraulic characteristics include the length, size, and condition of the pipe; types and sizes of fittings and appurtenances; and variations in elevation of the system. Since service and hydraulic characteristics constantly change, the design must incorporate allowances for these changes. Dynamic demographics of the users and deterioration of the system affect how...
