Construction of Open wells

CONSTRUCTION OF OPENS WELLS

Open wells may be constructed in following three ways:

1. Kacha wells or wells having no lining,
2. Wells having pervious lining and
3. Lined wells.

• These wells are of small depths and can be constructed in boulder or hard soils.
• They can be construct places where water table is very near to the surface of the ground.
• They can be only temporary source of irrigation water.
• They may collapse easily and thus sometimes prove very dangerous.

• In this, the lining of the well is done in dry bricks or stones without using any mortar.
• The seeping water can enter the well through the open joints of dry masonry.
• Thus inflow in this case is radial and not axial. Such wells are generally plugged at the bottom by means of concrete.
• If bottom is not plugged, then water will be entering the well both, from bottom as axial flow and sides as radial flow.
• When such wells are constructed in fine sandy soil, the pervious lining is generally surrounded by gravel to act as vertical filter.
• This vertical filter prevents ingress of sand along with seeping water.

• In this case wells are line by stone or brick masonry or by cement concrete.
• For constructing such a well first of all a pit is excavate with the help of hand tools.
• The diameter of the pit is kept slightly larger in diameter than the finish diameter of the well.
• After the pit has been dug a kerb is lai at its bottom and masonry is raise over it.
• The masonry is raised above ground.
• Now earth is excavate and bailed out of well and masonry is simultaneously raised over lining wall projecting above the ground level.