The Blackburn Brook is a stream in Sheffield, South Yorkshire, England which flows through the Blackburn Valley along the M1 and Ecclesfield Road and joins the River Don near the Meadowhall shopping centre. Downstream from the A61 road at Chapeltown the Blackburn Brook is defined as a main river by the Environment Agency, which requires new building development to be at least from the bank side as a flood defence measure and to allow access to the watercourse for maintenance. Course Blackburn Brook begins on the northern edge of High Green, the northernmost suburb of Sheffield, which is some from the city centre. It is formed from the waters of Storrs Dike, How Brook and Mark Brook, which meet within the boundaries of Westwood Country Park. Storrs Dike rises on the southern edge of Wortley Hall grounds, a grade II listed park and gardens created in the 19th century. It flows to the east and then the south east to the junction. How Brook rises to the west of the junction, and flows through a reservoir and the hamlet of Howbrook. Mark Brook rises to the south-west, and flows to the north east through Howbrook Reservoir to join the other two streams. The combined flow heads, broadly towards the south-east, passing over a weir, under Westwood Bridge, and entering another small reservoir. The outlet passes into a culvert, which carries it under what was a large refuse tip in 1967, and was the northern extremity of Thorncliffe Iron Works in 1905. Thorncliffe Iron Works and the adjacent Thorncliffe Colliery have been replaced with housing, and after a small pond and a short section of stream, the river enters a culvert beneath the housing by Newton Chambers Road, and emerges some considerable distance to the south-east, where it is joined by Charlton Brook, which rises from a series of springs to the west of the suburb of Charltonbrook. Both channels are crossed by the Penistone Railway line, and after the junction pass through a culvert beneath a warehouse complex, surface briefly, and pass through another culvert beneath houses and the A6135 Station Road. The brook turns to the south, and runs along the eastern edge of the housing at Chapeltown. It is crossed by the A619 Cowley Lane and the railway follows its western bank. After the B6087 Nether Lane bridge, it continues in a course that is further west than