4. Act to bind the Crown---(1) Except as provided in subsections (2)
 to (5), this Act shall bind the Crown.

   (2) This Act does not apply to any work or activity of the Crown
 which---
   (a) Is a use of land within the meaning of section 9; and
   (b) The Minister of Defence certifies is necessary for reasons of
         national security.

   (3) This Act does not apply to the exercise by the Crown of any
 function or power in relation to any national park within the meaning of
 the National Parks Act 1980, or any development or activity by the Crown
 in a national park, which---
   (a) Is a use of land within the meaning of section 9; and
   (b) Does not have a significant adverse effect beyond the boundary of
         the national park; and
   (c) Does not contravene section 13 (which relates to restrictions on
         use of the beds of lakes and rivers).

   (4) This Act does not apply to any work or activity of the Crown
 within the boundaries of any area of land held or managed under the
 Conservation Act 1987 or any other Act specified in the First Schedule
 to that Act (other than land held for administrative purposes)---
   (a) Which is a use of land within the meaning of section 9; and
   (b) Which does not contravene section 13; and
   (c) Which---
           (i) The Minister of Conservation certifies is necessary for,
         or incidental to, maintaining the intrinsic values of that area
         of land; or
           (ii) Conforms to a management strategy or management plan
         established under the Conservation Act 1987 or any other Act
         specified in the First Schedule to that Act.

   (5) No enforcement order, abatement notice, excessive noise direction,
 or information shall be issued against the Crown.