The water distribution system is the most important issue in human history and the water distribution system means providing sufficient water of appropriate quality and quantity.
The challenge to meet user demands also increased due to an increase in population and today a water supply system consists of infrastructure that collects, stores, treats, and distributes water between consumers and water sources.
To deliver water to the consumer with appropriate quality, quantity and pressure is the purpose of the water distribution system and for sustainable water supply, many efforts on the development of a water distribution system have been made.
Requirements of Good Water Distribution System:
There are the following requirements for the good water distribution system such as;
In the distribution pipes, water quality should not get deteriorated.
At all the intended places with sufficient pressure head, it should be capable of supplying water.
During firefighting, It should be capable of supplying the requisite amount of water.
During the repair of any section of the system, the layout should be in such a way that no consumer would be without water supply.
Above the sewer lines, all the distribution pipes should be preferably laid one meter away.
To keep losses due to leakage to the minimum, it should be fairly water-tight.
The Layout of the Water Distribution System:
In the layout of the water distribution system, the pipes are generally laid below the road pavements and generally follow the layouts of roads.
There are four types of the water distribution system and for a particular place, these types either singly or in combinations can be used.
Grid Iron System
Dead End System
Grid Iron System:
For cities with a rectangular layout where the water branches and mains are laid in rectangles, the gridiron system is suitable and this system also contains main lines, branch lines, and sub mains.
In this system by interconnecting all the lines, dead ends are eliminated and without stagnating, the water flows continuously in this system. For well-planned cities, the gridiron system is more suitable.
Advantages of Grid Iron System:
There are the following advantages of this system such as:
Without any dead ends or sediment deposits, the water will flow continuously.
Because of the interconnection of pipes, the head loss is minimum in this case.
For firefighting, the discharge will meet the required discharge.
Just by closing the cutoff valve in that line which does not affect the other users, the repair works can be easily done.
Disadvantages of Grid Iron System:
There are the following disadvantages of this system such as:
The pipes used in this system should be of large diameters and longer lengths because of circulating flow from all directions.
The design is difficult because in a particular pipe we cannot determine the accurate discharge, velocity, or pressure.
In this system, cutoff valves required should be more.
In this system, the main pipeline is provided around the city or area and the branch lines are connected with each other and projected perpendicularly and every street with the distributed area will get sufficient.
This system is also called a circular system and it is more suitable for a town with well-planned streets and roads.
Advantages of the Ring System:
There are the following advantages of ring system such as;
In this system, no stagnation of water occurs.
In the ring or circular system without affecting larger network repair work can be done.
For firefighting a large quantity of water is available.
Disadvantages of Ring System:
There are the following disadvantages of ring system such as;
Large diameter and longer length pipes are required in this system.
While laying pipes, skilled workers are necessary.
The numbers of cutoff valves are more.
In the radial system, the whole area is divided into small distribution zones and for each distribution zone an individual distribution reservoir is provided and the pipelines are laid radially to the surrounded streets from this reservoir.
With the mainline, all distribution reservoirs are connected and passing through the center of the city, and for areas with radially designed roads this system is suitable.
Advantages of Radial System:
There are the following advantages of the radial system such as;
With the high velocity and the high pressure the water distributed.
Because of quick discharge, the head loss is very small.
Easy to calculate the sizes of pipes.
Disadvantages of Radial System:
There are the following disadvantages of the radial system such as;
Because of the number of individual distribution reservoirs, the cost of the project is more.
Stagnation of water occurs in pipes due to many dead ends.
Dead End Water Distribution System:
In the dead-end system, the water does not flow continuously because it contains dead ends in the pipe system, and into several sub-networks, the whole pipe network is divided such as main lines, sub mains, service connections, and branch lines.
Firstly through the center of the city or area, one mainline is laid.
On both sides of the mainline, sub-mains are laid and then sub mains divided into branch lines and service connections are given from this.
Advantages of Dead End System:
There are the following advantages of the dead-end system such as;
The pipes can be easily laid in this system.
To make design calculations very simple, the pressure and discharge in each pipe can be determined very easily and accurately.
Based on the required demand of the population, the diameters of pipes of main, sub mains and branches can be designed so the cost can be reduced.
Less number of cutoff valves require.
Disadvantages of Dead End System:
There are the following disadvantages of the dead-end system such as;
In the remote parts, the pressure is not constant and is very less.
The whole portion should be stopped to repair if there is any damage occurs in the branch line.
For firefighting, limited discharge is available in this system.