Yorkshire Water is a British water supply and treatment utility company servicing West Yorkshire, South Yorkshire, the East Riding of Yorkshire, part of North Lincolnshire, most of North Yorkshire and part of Derbyshire, in England. The company has its origins in the Yorkshire Water Authority, one of ten regional water authorities created by the Water Act 1973, and privatised under the terms of the Water Act 1989, when Yorkshire Water plc, the parent company of the Yorkshire Water business, was floated on the London Stock Exchange. The parent company was Kelda Group in 1999. In February 2008, Kelda Group was bought by a consortium of infrastructure funds.