the Cornwall and Devon river authorities and part of the area of the Avon and Dorset River Authority. Southern Water Authority – The Isle of Wight and the areas of the Hampshire, Kent and Sussex river authorities, except the part of the area of the Kent River Authority which was included in the area of the Thames Water Authority. Thames Water Authority – The Thames Catchment Area, the Lee Catchment Area and parts of the area of the Essex River Authority and of the Kent River Authority that drained to the Thames estuary Welsh National Water Development Authority (WNWDA) – Including all the catchments of the Wye River Authority, the Usk River Authority, the Glamorgan River Authority, the South West Wales River Authority, the Gwynedd River Authority and the Dee and Clwyd River Authority. Parts of the WNWDA area including parts of the River Dee and the River Wye extended into England Wessex Water Authority – Most of the area of the Avon and Dorset, Bristol Avon and Somerset river authorities and part of the area of the Severn River Authority draining to the lower Severn estuary Yorkshire Water Authority – The area of the Yorkshire River Authority Governance of the regional water authorities was by boards of governors. The Secretary of State for the Environment, or the Secretary of State for Wales in the case of the Welsh Authority, appointed the chairman, and between six and twelve other members, while two more members were appointed by the Minister of Agriculture, Fisheries and Food. The size of the board differed from authority to authority, with the smallest being 14 governors plus a chairman for Wessex Water and South West Water, and the largest being Thames Water, with over 50 members. Over half of the members were nominated by local authorities, and so the statutory appointments were normally based on technical expertise, to complement the more local interests of local authority appointments. By the mid-1980s, the water authorities had an annual turnover of around £2,600 million, and employed some 51,000 people. Their major concern was the provision of potable water and the treatment of sewage, with environmental services occupying a much smaller part of their activities. They managed of water mains, 850 water treatment works, of sewers and 6,500 sewage treatment works. Although all aspects of water management were under one body for each region, the new authorities still had to