Dug or Open Wells:

In open or dug wells, a hole is made into ground till the flow of water is reached. The depth and the diameter of hole is decided on the basis of seepage area to be exposed for intercepting and the required yield from the sub-soil. Its diameter may vary from 2 meter to 9 meter and depth is normally less than 20 meter. To prevent entry of water directly from the surface, a watertight steining up to few meters below the vertical zone of pollution (normally 3 to 5 meter or more below natural ground surface) is provided. The walls of the steining are normally made of pre-cast concrete or brick/stone masonry and its thickness is kept between 0.50 to 0.75 meter depending on the depth of the well. This method is suitable for water discharge upto 10 m³/hour.

Figure: Dug or Open Well