Sustainable Living: 3M FuturewiseTown PlanIntroductionGo BackGo Next3M


ReservoirDisadvantages of irrigation

  • In tropical areas of high evaporation, salts in the soil are drawn up to the surface through capillary action as irrigation water sits in channels. This eventually makes the soil too salty to grow plants.
  • As water sits in irrigation channels malarial mosquitoes and bilharzia snails can breed.
  • Huge quantities of silt build up behind dams. Undammed rivers flood and deposit silt along the riverbanks. This provides fertile topsoil to the land. Without natural fertiliser in the form of silt, artificial fertilisers need to be bought. Fertilisers can get into the river and cause eutrophication (lack of oxygen), destroying fishing.