Isetyenziselwa ukuvavanya, ukuvavanya kunye nokubeka amanqaku kwindlela esebenza ngayo ilaphu emanzini angamanzi. Isekelwe ekuchongeni ukumelana namanzi, ukungakwazi kwamanzi kunye nokufunxwa kwamanzi okubonakaliswa yisakhiwo selaphu, kubandakanya ijiyometri kunye nolwakhiwo lwangaphakathi lwelaphu kunye neempawu ezinomtsalane wemicu yelaphu kunye nemisonto.