There may be more than one sources available to water supply in any community or city\town etc. Some major factors should be considered while selecting the sources such as location, quality, reliability and cost.
Sources should be near to the town or villages and not far from consumers area as possible. Sources should be at higher elevation so that gravity flow can be maintained.
Quality of water:
Sources must have sufficient quantity of water to meed the demand of through out the year.
Reliability of sources:
Sources must be reliable. Its should be perennial and must not be used for another purpose by other purpose.
Quality of water: The quality should be very good and useful for drinking purpose without any treatment or very less treatment i.e. easily and cheaply treated therefore it must be away from waste discharges as far as possible.
Cost of waste supply must be minimum. Cost depend upon the various factor like: system of supply, ground level distance from the sources, treatment required, distribution system etc.
If the population of the society, town or village is high; then the water demand will be high. So , source having higher production of water for long time should be choosed.