It also covered a small part of the counties of Rutland, Worcestershire and Shropshire.
The major cities within the authority's area included Wolverhampton, Birmingham, Walsall, Stoke-on-Trent, Leicester, Derby and Nottingham.
The authority was constituted by Order of the Minister of Housing and Local Government dated 18 June 1964 and consisted of 39 members, 20 of whom were appointed by county councils and county borough councils in its area.
The authority had a number of committees each dealing with a different aspect of its work and it operated through four departments as follows: Under the Land Drainage Act 1930, the authority was responsible for the maintenance of what are still termed main rivers which, as the name implies, were the most important stretches of water channels within its area.
The total length of statutory main river which the authority was responsible for was 905 miles [1,445 km].