The dominant owner cannot, by merely altering or adding to the dominant heritage, substantially increase an easement. Where an easement has been granted or bequeathed so that its extent shall be proportionate to the extent of the dominant heritage, if the dominant heritage is increased by alluvion, the easement is proportionately increased, and, if the dominant heritage is diminished by dilluvion, the easement is proportionately diminished.

Save as aforesaid, no easement is affected by any change in the extent of the dominant or the servient heritage. Illustrations/br