The River Don (also called Dun in some stretches) is a river in South Yorkshire, England. It rises in the Pennines and flows for 112 km (70 miles) eastwards, through the Don Valley, via Penistone, Sheffield, Rotherham, Mexborough, Conisbrough, Doncaster and Stainforth.
It originally joined the Trent, but (re-engineered by Vermuyden as the Dutch River), now joins the River Ouse at Goole in the East Riding of Yorkshire.
Don Valley is the local UK parliamentary constituency near the Doncaster stretch of the river. The Don's major tributaries are the Loxley, the Rivelin, the Sheaf, the Rother and the Dearne.
Along the Sheffield–Rotherham stretch of the river are five weirs that punctuate a local walking and cycling route: the Five Weirs Walk.
A further walk, the Upper Don Walk is being developed that will make it possible to walk or cycle from Sheffield city centre up to Oughtibridge
The industrial nature of the region has led to a severe pollution problem for the river, although this has abated somewhat over recent years, with salmon reported in the river near Doncaster.
Fig trees grow on a stretch of the river bank in Sheffield; the seeds having germinated successfully thanks to the increased warmth of the water near factory outfalls.
The Don derives its name from Dôn (or Danu), a Celtic mother goddess.
Navigation to Sheffield was made possible by using canal cuttings to avoid circuitous and unnavigable sections of the Don as far up as Tinsley, and then by a canal from Tinsley to Sheffield. The cuts and navigable river sections (with two canals connecting the Don to the Aire and Calder Navigation and the River Trent respectively) constitute the Sheffield and South Yorkshire Navigation.
The lower Don originally meandered in a north-easterly direction across the marshland of Hatfield Chase to enter the Trent just above its junction with the Ouse. It formed the boundary between Yorkshire and Lincolnshire.
In the marshland drainage project of 1627, the civil engineer Cornelius Vermuyden from The Netherlands diverted the Don northwards and then eastwards to enter the Ouse at the site of Goole, 15km upstream of the Trent. The "Dutch River" so formed had the advantage of being navigable by small coal barges which transferred their cargo to sea-going vessels at the Ouse.
The construction of the railway from Doncaster to Goole in 1870 greatly reduced this traffic and when the cut-off New Junction Canal from Stainforth to the Aire and Calder Navigation (Knottingley and Goole Canal) west of Goole was completed in 1897, the Dutch River reverted almost entirely to its original drainage function.
The Stainforth and Keadby Canal allows navigation from the Don at Stainforth to the Trent at Keadby.
In June 2007 there was catastrophic flooding along the River Don due to record levels of rainfall. The city of Sheffield and the town of Rotherham were severely hit with two people dying in the area.
Parts of Doncaster, including the Bentley and Sprotbrough areas, also suffered severe flooding and many people were evacuated from their homes. On Thursday 28 June 2007, Doncaster became the worst hit area of the floods, with both the RAF and the Army called in to help with evacuations and help with controlling the rising water levels.