Ukushintsha kwesimo sezulu kanye nokuthuthuka okusheshayo kwezimboni zomhlaba wonke kanye nezolimo kwenze inkinga yokuntuleka kwemithombo yamanzi ahlanzekile ibe nkulu kakhulu. Ngokwezibalo zeBhange Lomhlaba, i-80% yamazwe nezifunda emhlabeni ayinawo amanzi ahlanzekile okusetshenziswa izakhamuzi nezimboni. Imithombo yamanzi ahlanzekile iya ngokuya intula, kangangokuthi amanye amadolobha asogwini nawo abucayi. Ukuntuleka kwamanzi. Inkinga yamanzi isibeke phambili isidingo esingakaze sibonwe sokuchithwa kwamanzi olwandle. izwe lami linamakhilomitha-skwele angaphezu kwezigidi ezi-4.7 ezilwandle ezimaphakathi nezwe kanye nezilwandle ezisemngceleni, likleliswe endaweni yesihlanu emhlabeni, elinemithombo yamanzi olwandle amaningi kanye namandla amakhulu okuthuthuka.