The Lee Valley Regional Park Authority is a statutory authority responsible for managing and developing the Lee Valley Regional Park. The park consists of approximately 10,000 acres and stretches along a 26 mile length of the River Lee in Greater London, Essex and Hertfordshire. The authority came into existence on 1 January 1967. The authority's board consists of 28 members appointed by the various local authorities in the area. Those appointed by councils of districts through which the Lee flows are known as "riparian" members, those appointed by other councils as "non-riparian" members.