The Thames Water Authority was one of ten regional water authorities created in the UK in 1975 to bring together all the water management functions of the region in one public body.
The bodies subsumed included the Metropolitan Water Board, the Thames Conservancy, the Lee Conservancy Catchment Board and parts of the Essex River Authority and the Kent River Authority which had formerly regulated the north bank and the south bank of the River Thames estuary.
In 1989 the Thames Water Authority was partly privatised, with the water and sewage responsibilities transferring to the newly established publicly quoted company of Thames Water, and the regulatory responsibilities transferring to the newly created National Rivers Authority