law: Indian Easements Act, 1882
  38. Extinction by release
  An easement is extinguished when the dominant owner releases it,
  
  expressly or impliedly, to the servant owner.
  Such release can be made only in the circumstances and to the
  
  extent in and to which the dominant owner can alienate the dominant heritage.
  An easement may be released as to part only of the servant
  
  heritage.
  Explanation I: An easement is impliedly released-
  (a) where the dominant owner expressly authorizes an act of a
  
  permanent nature to be done on the servant heritage, the necessary consequence
  
  of which is to prevent his future enjoyment of the easement, and such act is
  
  done in pursuance of such authority;
  (b) where any permanent alteration is made in the dominant
  
  heritage of such a nature as to show that the dominant owner intended to cease
  
  to enjoy the easement in future.
  Explanation II:  Mere non-user of an easement is not an
  
  implied release within the meaning of this section.
  Illustrations
  (a) A, B and C are co-owners of a house to which an easement is
  
  annexed. A, without the consent of B and C, releases the easement. The release
  
  is effectual only as against A and his legal representative.
  (b) A grants B an easement over A’s land for the beneficial
  
  enjoyment of his house. B assigns the house to C. B then purports to release
  
  the easement. The release is ineffectual.
  (c) A, having the right to discharge his eavesdroppings into B’s
  
  years, expressly authorizes B to build over this year to a height which will
  
  interfere with the discharge. B builds accordingly. A’s easements is
  
  extinguished to the extent of the interference.
  (d) A, having an easement of light to a window, build up that
  
  window with bricks and mortar so as to manifest an intention to abandon the
  
  easement permanently. The easement is impliedly released.
  (e) A, having a projecting roof by means of which he enjoys an
  
  easement to discharge eavesdroppings on B’s land permanently alters the roof,
  
  so as to direct the rain-water into a different channel and discharge it on C’s
  
  land. The easement is impliedly released.