For efficient distribution it is required that water should reach to every consumer with repaired rate of flow. Depending upon the methods of distribution, the distribution system is classified as follows (Twart, 1990);
1) Gravity System
2) Pumping System
3) Dual System of Combined Gravity and Pumping.
2.2.1 Gravity System:
When some ground sufficiently high above the city area is available as seen in Figure 1 below, this can be best utilized for the distribution system in maintaining pressure in water pipes, the water flows in the mains due to gravitational force.
As no pumping is required, therefore it is the most reliable system for the distribution of water. The water head available at the consumers door is just minimum required and the remaining head is consumed in frictional other losses.
