Depending upon topography of the town, the water may be distributed by

1. Plumbing

2. Gravity

3. Combine of pumping and gravity (dual system)

1. Pumping system

• The treated water is directly pumped into distribution mains without storing in high level reservoirs. High lift pump are provided for forcing water into mains.

• Since the water is fluctuating the pumps have to operate at various rate during the whole day. A continuous attendance is required at the pumping station to regulate the flow by running only the required number of pump out of total number of pump install.

• During failure of pump and electric supply the water supply to the town may be interrupted to avoid this it is desirable to have some units of pump running on diesel.

• Pumping system can supply the required quantity of water for firefighting by running all pumps including standby. The system is costly and its use should be discourage as far as possible.

Advantages

A. Large quantity of water available in case of fire.

B. Suitable for any type of topography.

Disadvantages

A. Sufficient water required.

B. Not economical.

C. More losses and wastage.

2. Gravity system

• In this system the gravity force is used in distribution water from high level source to low level zone consumers.

• This eliminates pumping altogether. The method is economical reliable and required less maintenance. For proper working of the system the difference of head available between

• Service reservoir and low level zone should be sufficient to develop enough pressure at consumers tap. The method also minimises wastage and leakages.

Advantages

A. Simple and economical.

B. Less maintenance.

C. Less leakage and wastage.

D. Reduction in pipe sizes.

Disadvantages

A. Not suitable if source is not a sufficient elevation to cause flow under gravity.

B. Cannot provide high pressure for fire demand.

3. Combine of gravity and pumping system

• In this system the water after treatment is pumped and stored in the elevated services reservoir (ESR) according to the supply hours the store water supply to the public by gravity.

Advantages

A. The system is economical, efficient and reliable and adopted practically everywhere.

B. Pumping at constant rate increases efficiency.

C. Special supervision is not required.

D. Fire demand efficiently met with.

E. Water is available even during failure of pump and power.

 Layout of distribution pipe network.

Distribution pipe are always laid below the roads prevailing in the town. Also they are laid on one side of the road, keeping the other side of the road for laying of sever in future. The layout of pipelines naturally fallows the pattern of road.

Following are the four type of system.

1. Tree end system

2. Ring or circular system

3. Grid or interlaced system

4. Radial system.

1. Tree end system (dead end system)

In this system there is one main pipe line is laid along main road and submain branches minor distributary are laid along the other road and streets connecting main road.

This system is also known as dead end system.

Suitability

Tree system is used in town or cities which are not well planner.

Advantages

A. Cheap in initial cost

B. Easy determination of pipe size

C. Laying of pipe simple

D. Less number of valve are required.

Disadvantages

A. This system cannot meet fire demand

B. Due to stagnation water get polluted.

2. Ring or circular system

In this system the area is divided into blocks.

Water mains are laid around the blocks from all side.

The branches submain are taken along inner road and interconnected.

Suitability

This system is suitable for well-planned cities.

Advantages

A. Water is available for fire demand.

B. Designation of pipe is simple and easy.

Disadvantages

A. The system is costly to construct.

B. It is required more length of pipe and more number of slice valves.

3. Grid or interlaced system

A main pipe is laid along main road and submain branches are laid along inner road and interconnected so that water remain in circular and there are no dead end.

Suitability

Grid iron system is suitable for well-planned cities. Where the roads are at right angle to each other.

Advantages

A. There are no dead ends so water is not stagnated.

B. Size of pipe is reduced.

Disadvantages

A. More number of valves is required.

B. Costly

C. Longer length of pipe required.

4. Radial system

The system consist of laying pipeline radially end of the periphery of the area of the zone.

In end zone elevated service reservoir is placed at it centre from where water is admitted to this radially laid pipe known as branches.

Suitability

This system is suitable for localities having radial pattern of road.

Advantages

A. Designation of pipe size is simple

B. There is quick and efficient supply of water.

Disadvantages

A. As every zone required a separate service reservoir number of reservoir required more and hence the systems become costly.