The Metropolitan Water Supply Sewerage & Drainage Board was established on the 1 July 1964 to operate as a Board with borrowing powers similar to other State owned enterprises. The Board initially consisted of seven members, all viceregal appointees.

The Authority came into existence as from the 1 July 1982 pursuant to Statute 36 of 1982. This Act was the result of a legislative review conducted since 1978 with the intention of gradual replacement of obsolete provisions of the 1909 legislation (No. 43 of 1909).

The new legislation provided that "subject to the Minister, the Authority shall be administered by a Board of Management to be known as the Metropolitan Water Board". The Board consisted of seven viceregal appointees three of whom were Authority employees, and four, external appointees. The Chairman was appointed by the Governor for five years. The property, powers, functions (etc) of the former Board were transferred to the Authority by the new Act.

Following the election of a Labor Government in February 1983, a steering committee was appointed to oversee the merger of the Authority and related water activities of the Public Works Department. The new omnibus organisation (i.e. the Water Authority of Western Australia) received legislative basis through the Water Authority Act of 1984. The new Authority commenced operations as from 1 July 1985.

The Water Authority of Western Australia held responsiblity for the construction, operation, maintenance and control of water, sewerage and main drainage facilities within the State. The Water Authority was formed in July 1985 and merged the Metropolitan Water Authority with the country water activities of the Public Works Department. The Water Authority was replaced by the Water Corporation on 1 January 1996.

The Water Corporation was established as a body corporate under the Water Corporation Act 1995 and assumed the functions of the Water Authority of Western Australia on 1 January 1996. The Water Corporation is now the principle water utility for Western Australia and provides water, wasterwater, drainage and irrigation services to the State.