(1)In any case where a regional scheme is in operation, any local authority or joint committee may by resolution decide to prepare a scheme with respect to any land to which the regional scheme applies, being land in, or in the neighbourhood of, the district of the local authority or, as the case may be, the districts of any of the constituent authorities, or to adopt, with or without modifications, a scheme proposed by all or any of the owners of any such land.
(2)A scheme prepared or adopted under the preceding subsection (in this Act referred to as a " supplementary scheme ") shall incorporate, with or without modifications, all such provisions of the regional scheme as relate to the area to which the supplementary scheme applies and are not inconsistent with the provisions thereof, and may include such additional provisions as appear to be necessary or desirable.
(3)A resolution to prepare or adopt a supplementary scheme shall not affect the operation of the regional scheme or the powers of any authority thereunder, but as from the date on which the supplementary scheme comes into operation it shall, so far as respects the area to which it applies, have the effect of revoking the regional scheme.
(4)In this section the expression " regional scheme " means a scheme made, whether under this Act or under any Act repealed by this Act, by a joint committee.