Severn Trent Water Authority and predecessor bodies, including Derwent Valley Water Board Unlisted accession, Feb 2016 North Derbyshire Water Board: River Derwent Scheme Booklet, Aug 1973; Annual Inspection of Undertakings 1967-1972 (6 files); 'Engineering 100' Return of Water Undertakings, 1972; First Inspection of the Undertaking, 1963 Severn Trent Water Authority: Hydrometric Yearbook 1974-1975 (Parts 1 and 2); Bamford Water Treatment Works showing modernisation in the 1980s leaflet; Booklet. Severn Trent Engineering Carsington Water: Building for the 21st century [1990s] South Derbyshire Water Board: 'Engineering 100' Return of Water Undertakings, 1971, annotated with 1973 figures?; A review 1961-1974; Official Opening of Homesford Water Treatment Works Booklet 7 July 1970 Chesterfield, Bolsover and Clowne Water Board: Annual Inspection, 1963; Annual Statistical Tables, 1959; Annual Report on Water Treatment and Examinations, 1960 Derwent Valley Water Board: Plan of Rowsley Waterworks and mains layout, 1936 Chesterfield RDC: Plan of Sewer Layout for Stonebroom Industrial Estate [pre-1974] 19th-20th cent