Geography of Sheffield (Totley Brook passes south of Totley and meets Old Hay Brook at Needham's Dyke). The Sheaf flows northwards to join the River Don near Blonk Street Bridge in the city centre. This lower section of the River Sheaf together with the River Don, between the present Blonk Street and Lady's Bridge, formed part of the perimeter of Sheffield Castle. Porter Brook's source is just inside the Peak District National Park, to the west of the city, at Clough Hollow, also near Ringinglow. From here it flows eastward to meet the Sheaf, at a point now located underneath Sheffield Midland Station.
Sheffield City Region Combined Authority Sheffield City Region Combined Authority The Sheffield City Region Combined Authority (formally the Barnsley, Doncaster, Rotherham and Sheffield Combined Authority) is the combined authority for South Yorkshire in England, with powers over transport (public transport and major trunk roads only), economic development and regeneration. The combined authority does not formally cover all of the "Sheffield City Region" as it does not include areas of northern Derbyshire and Nottinghamshire which are part of the city region. However the district councils of those areas of Derbyshire and Nottinghamshire are represented on the combined authority as non-constituent members. The authority's first mayoral election