108.Section 61 states that the fixing of the position of the boundary shown on land registry plans does not prevent the adding of land by accretion or the removal of land by diluvion. This happens when the natural boundary between land and water changes gradually over time, in particular where land is formed by deposits from the sea (accretion) or washed away by waves (diluvion). In normal circumstances the adjoining landowners’ title would be extended or diminished as a result of the changes. If several landowners have made an agreement that the natural boundary changes will not have that legal effect, for example in relation to the location of a stream, then that agreement will only take effect if it is registered. Rules will govern how that is to be achieved.