Changes

[[Image:refilled well.jpg|thumb|right|250px|Refilled well]]

[[Image:rooted reservoir well.jpg|thumb|right|250px|rooted reservoir well]]

Refilled wells are commonly used in Asia and in other parts of the world. A well is excavated with temporary walls. A ferrocement tank is then placed in the bottom. A pipe and pump are installed, after which the well is refilled with soil. The advantage of this is that building them is very inexpensive, since the walls do not need to be coated. The water is also protected better against contamination. However when the water table drops during years of drought, no possibility exists to deepen them.