The Lee Conservancy Board was a statutory body established to administer the River Lee Navigation, to keep the river free from pollution, and to allow the abstraction of water. The board came into its powers in April 1869 and in 1911 also became responsible for the River Stort Navigation.
The original board had 15 members. 8 were elected: 7 by the Trustees of The River Lee (a body established by parliament in 1738, and whose powers were assumed by the new board) and 1 by the barge owners using the river; 7 were appointed: 1 by the New River Company, 1 by the East London Waterworks Company, 2 by the Board of Trade, 1 by the Corporation of London, 1 by the Metropolitan Board of Works and 1 by the Undertakers of the Navigation of the River Stort.
Over time the legislation was amended and the nominating bodies changed: the London County Council replaced the Metropolitan Board of Works and the Metropolitan Water Board replaced the East London Waterworks Company.
The board was abolished in 1948 when waterways were nationalised: it was replaced by the Lea District of the British Transport Commission. The commission was itself abolished, and many of the functions are now carried out by the British Waterways Board.
They should not be confused with the Lee Conservancy Catchment Board (LCCB) which was an entirely different body that was established in 1930. The LCCB originally consisted of the members of the Lee Conservancy Board with six additional members. It was abolished in 1974 becoming part of the Thames Water Authority.