Water is polluted by natural means like flood and rainfall. As a result of flood many impurities are mixed with water. Water is mostly polluted by man-made causes. Industrial wastes, household garbage, rainwater containing chemical fertilizer and insecticide, all these mixed with water make it polluted. Due to water pollution extreme harm is caused to aquatic plants and animals. The oxygen content of water becomes reduced and thus many fishes and aquatic animals die and float on the water surface. There are strict regulations against water pollution in European countries.
All water transport vessels are to take necessary measures so that their oil and waste materials do not pollute water. Chemicals released by smokestacks (chimneys) can enter the atmosphere and then fall back to earth as rain, entering seas, rivers, and lakes and causing water pollution. There are provisions of severe punishment or heavy penalties if such measures are not taken. To prevent water pollution in our country primarily people should be motivated through different medias. Later regulations should be implemented very strictly and impartially.