Service reservoirs, also known as distribution reservoirs, store treated water for supplying water to consumers. There are three main types: surface reservoirs built at ground level, elevated reservoirs built on towers above ground level, and stand pipes which are tall cylindrical tanks resting on the ground. Distribution reservoirs serve to equalize variations in hourly water demand, maintain water pressure in the distribution system, and provide time for disinfection of water before supply. They have components like inlet/outlet pipes, overflow pipes, and indicators to monitor water levels. The total storage includes balancing storage to meet fluctuating demand, breakdown storage for emergencies, and fire storage for firefighting needs.