After reading this article you will learn about the open wells and tube wells with the help of a diagram.
Water wells can be classified either open wells or tube wells. Open wells have relatively large diameter (generally 1 to 5 m) and low yields (generally less than 30 m3/hr), and are not very deep (generally 3 to 15 m). Since these wells are constructed by digging, they are also known as dug wells. The walls of an open well may be of either brick (or stone) masonry or precast concrete rings.
Open wells can be either shallow open wells or deep open wells. A shallow open well drains its supplies only from the top upper aquifer. But deep open wells are those which rest on an impervious stratum and draw their supplies from the previous water-bearing stratum lying below the impervious stratum through a bore hole made in the impervious stratum. As shown in Fig. 4.4, a deep open well can have its depth smaller than a shallow open well in the vicinity.
A tube well is in the form of a long pipe with holes (or slots) at suitable locations and which is sunk into the ground intercepting one or more aquifers. The diameter of a tube well is usually in the range of about 8 to 60 cm. The depth of a shallow tube well is usually limited to about 30 m. A deep tube well can have depths up to about 600 m.