Title is said to arise from natural causes in the cases of accretion and reliction. Accretion is the increase of land caused by gradual and imperceptible additions thereto caused by the washing of the sea or adjacent stream. Reliction is the gradual subsidence of waters leaving dry land where there had formerly been water. The land created either by accretion or reliction belongs to the adjacent owner.

The sudden removal or deposit of land by the perceptible action of water is called avulsion. The title to land cannot be changed or created by avulsion.