Selection of Source of Water:

In selecting a particular source of water for a town or city following important points are generally considered:

The Quantity Available

The quantity of water available from the source must be sufficient to meet the various demands during the entire design period of the scheme.

Water Quality

The water available from the source must not be toxic, poisonous or in any other way injurious to health. The impurities present should be such so as to be removed easily and economically by normal and standard treatment methods.

Distance of the Source

The source of water should be situated as near the city or town as possible. When the distance between source and city is less, lesser length of pipe conduits are required which are quite costly.

General Topography of the Intervening Area

The area or land between the source and the city should not be quite uneven. It should not contain deep valleys and high mountains. In case of such uneven topography, the cost of trestles of carrying water pipes in valleys and that of constructing tunnels through mountains will be enormous.

Elevation of the Source of Supply

The source of water must be on a high contour, lying sufficiently higher than the city so as to make the gravity flow possible. When water is available at lower elevation than the average city level, pumping has to be resorted which involves huge installation and operational cost.