In Mauritius water supply is normally soft water. During dry season, there is water cut for certain periods by C.W.A. As there is no water in the pipe, a layer of oxide is formed in the pipe. After a few years, the inner diameter of the pipe is reduced by the oxide formed in the pipe. For that reason, the C.W.A must replace the main pipes affected by the oxidation after a certain period.
A similar problem occurs in car radiators and in certain types of water pump which are affected by oxidation because they are not used frequently.