The reason for writing this article is that my water supply is not so good but I am residing in a good area of Chennai-A metropolitan city of India. There is a need to make the water supply proper, so that people will use the water safely and conveniently. The main genuine reason of a water supply system is to supply safe and whole some water to consumers by providing water in adequate quality and quantity. By making water easily available to consumers so that people use water comfortably for their different needs.
There are two sources of water supply, namely;
(a) Surface water
Rivers - River is nothing but the water deposited from the rain water and continuous flow along the slope of the earth to meet the sea.
Lakes – Lakes are the small something like which when coming from the big dams.
Impounding reservoir – Also called Ponds and dams are also in these categories.
(b) Ground water
Springs
Infiltration galleries
Wells- The underground water is under this types of well. The long deep dug in the earth to get the underground water for various uses are called well.
Steps involved in planning of a water supply scheme
(a)Fixing the design Period- They is usually designed to meet the requirement over a 30 year period after their completion. This makes the people secure and not to worry for water in future. The fixing of design taps is very necessary for a long time investment of money. The design period plays an important role in providing facility to public.
(b) Estimating the required amount of water- This involves determining the number of people who will be covered and per capita consumption and thus the required amount of the water. According to the number of people using the water bulk tank and in bulk taps are fixed in the societies. These bulk tanks and bulk taps are continuously and timely filled with water for common public use.
(c) Deciding the source of supply- It is by considering the quality and quality of water available from different sources and their locations. Dams are the major source of water. They also use ponds for the fulfillment of water for supply. Ultimately the rain water is the main source of water for supply. The rain water is come to deposit in the reservoir tanks, dams and various ponds then it is disinfected from various impurities and then releases to public use through tape.
(d) Design of elements
Reservoir and intake works- In this method the water is collected from the various sources and then reserved for the next process.
Conveying mains- The sending of water to the treatment plant for the purification is called conveying mains.
Treatment plant- These are the bulk purification where the refinement of the water takes place.
Balancing reservoirs- Balancing reservoir is water taken after purification are ready for the distribution.
Distribution system- Finally purified water is ready for the distribution to the domestic uses with the help of pipelines.
Consumption for various uses
Domestic - Around 50% of total consumption in an average city
Commercial and industrial- Depends on number and type of industry
Public uses- About 10 %
Loss and waste- About 15%
Fire demand- Considered as a function of population
Per-capita consumption
Per capita consumption is expressed in litre per capita per day (lped)
lped = Q/P*365
Q -> Total quantity of water in litres required per year.
P-> Population
For India, lped is 135
Factors affecting per capita consumption
Climate, Class of consumers, Industries and commerce, Quality of water, Extent of water system, Pressure of distribution system, System of supply, Size of the city.