The first authority charged with managing navigation and lock building was the Oxford-Burcot Commission, which built the locks at Iffley and Sandford below Oxford in 1633 and at Swift Ditch near Abingdon. In 1751, the Thames Navigation Commissioners were established and built eight locks between Shiplake Lock and Boulters lock between 1770 and 1773. The opening of the Thames and Severn Canal from Lechlade in 1789 led to the building of many of the locks upstream of Shiplake. The six locks built by the City of London Corporation on the tidal section below Staines between 1811 and 1815 required individual Acts of Parliament, and the Thames Conservancy took over their management from the City in 1857. In 1866 the Thames Conservancy became responsible for all river management and installed more locks over the years, the last being Eynsham and King’s in 1928. In 1908 an Act transferred responsibility for the Thames from a point below Teddington Lock to the Port of London Authority, and this included Richmond Lock. The Thames Conservancy was subsumed into the Thames Water Authority in 1974. With the privatization of water supply in 1990 the river management functions passed to the new National Rivers Authority and in 1996 to the Environment Agency. Only Richmond Lock remains under the jurisdiction of the Port of London Authority.