4Restriction on discharge of functions by local authorities within port health district.
(1)A local authority having jurisdiction in any part of a port health district, including the port health district of the port of London, shall cease to discharge in relation thereto any functions which are functions of the port health authority:
Provided that, with the approval of the Minister, the port health authority of any such district may by agreement delegate, with or without restrictions or conditions, any of their functions to a riparian authority whose district lies within, extends into or abuts on, the district of the port health authority.
(2)Where under the preceding subsection any functions of a port health authority are delegated to a riparian authority, the riparian authority in the discharge thereof shall act as agents of the port health authority.