Unground sources

Following are the four in which undergrounded sources are found

• Infiltration galleries
• Springs
• Wells

Infiltration galleries

An infiltration gallery is a horizontal or nearly horizontal tunnel which is constructed through water-bearing strata. It is sometimes referred to as the horizontal well.
The gallery is usually constructed of brick walls with slab roof. The gallery obtains water from the water-bearing strata by various porous drain pipes are converted with gravel pebble etc. so as to prevent entry of very fine material into the pipe. The gallery is led to a sump from where it is pumped and supplied to consumers after proper treatment. The infiltration galleries are used as a source of water supply when groundwater is available in sufficient quantity just below ground level. The galleries are usually constructed at depth of about 5 to 10 meters from the ground level.

Infiltration wells

In order to obtain large quintiles of water, the in infiltration wells are sunk in series in the banks of the river. The wells are closed at the top and open at the bottom. They are constructed of bricks masonry with open joints. The water infiltrates through the bottom of such wells and as if has to pass through.
The bottom of such wells and as if has to pass through sand bed, it gets purified to some extent. The infiltration wells, in turn, are connected by porous pipes to a collecting sump, know as jack well and the water thus collected through the infiltration wells then flows by gravity into jack well is pumped to the purification plant for treatment.

Springs

When groundwater appears water at the surface for many reasons, the spring is formed. The server source of water supply for small towns, especially near hills or bases of hills. A goal spring proves to be a sure source of water but is difficult to find a good spring for the purpose of water scheme. However, when a spring is to be developers as a source of water supply the following factors should be carefully ascertained.