(Vukasin et al. 1995)

This illustration of the water cycle shows the way of the water from the ocean, through the atmosphere, brought back to the earth by rain, evaporating again or flowing back to the see, either as surface water or in groundwater flows (Vukasin et al. 1995).

Different types of wells (Cairncross 1993)

Example of a dug well with a handpump.

Example of a driven well with a handpump (Wagner and Lanoix 1959).

Example of a sanitary rope-and-bucket-well (Wagner and Lanoix 1959).