Types of wells

1. Dug well:

• Also called open well which is dug down to water bearing strata or confined aquifer.
• They drive water from the formations close to the ground surface.
• The large diameter of open well permits the storage of large quantity of water in the well.
• In Nepalese context, the depth of well is found upto 4-7 feet.

2. Tube well:

• Constructed by fixing a pipe below ground surface and passing through different geological formations.
• It consists of water bearing and non-water bearing strata.
• Blind pipes are located at the non-water bearing strata and perforated pipes are placed against the aquifer.
• The well casing rests over a confined water bearing formation of sand and gravel water enters the well through bottom only.
• According to pumping water level, tube wells are classified into:-

a) Shallow tube well:

• Homemade tape.
• Wells are generally dug upto 10-25 m deep below the ground level.
• A metal or plastic pipe with a screen is lowered and water is discharged with the help of pump.
• The well is bore to a stratum having coarse sand or sand with gravel and the supply is drawn from the surrounding material.

b) Deep well:

• Made when water is not available even with 75-100 m depth.
• Constructed by fixing a pipe below the ground surface and passing through different geological formations consisting of water bearing and non-water bearing strata.