law: Water (Prevention and Control of Pollution) Act, 1974
  19. Power of State Government to Restrict the Application of the Act to Certain Areas
  
  (1) Notwithstanding anything contained in this
  
  Act, if the State Government, after consultation with, of on the recommendation
  
  of, the State Board, is of opinion that the provisions of this Act need not
  
  apply to the entire State, it may, by notification in the Official Gazette,
  
  restrict the application of this Act to such area or areas as may be declared
  
  therein as water pollution, prevention and control area or areas and thereupon
  
  the provisions of this Act shall apply only to such area or areas.
  (2) Each water pollution, prevention and control area may be declared either by
  
  reference to a map or by reference to the line of any watershed or the boundary
  
  of any district or partly by one method and partly by another.
  (3) The State Government may, by notification
  
  in the Official Gazette, -
  (a) alter any water
  
  pollution, prevention and control area whether by way of extension or
  
  reduction; or
  (b) define a new water
  
  pollution, prevention and control area in which may be merged one or more water
  
  pollution, prevention and control areas, or any part or parts thereof.