It rises in eastern Cambridgeshire, passes to the east of Haverhill, through Cavendish, Sudbury, Bures, Nayland, Stratford St Mary and Dedham.

The entire non-tidal river above Manningtree is designated as the Dedham Vale National Landscape, formerly known as an Area of Outstanding Natural Beauty.

A third extraction point was added near Brantham, so that volumes of water flowing through Flatford could be maintained at a higher level for the benefit of tourists.

[3] However, the river-name Stour, common in England, does not occur at all in Wales;[4] Crawford noted two tributaries of the Po River near Turin, spelled Stura.

As an adjective, with Germanic roots, it signifies "large, powerful" (in present-day Scandinavian languages stor means "big, great").

[citation needed] The river rises in Wratting Common, Cambridgeshire, to the south of Weston Colville, and passes near Great Bradley where it is joined by Kirtling Brook.

The River Glem joins it on the left bank, before it passes to the west of Long Melford and then skirts the western and southern edges of Sudbury.

To the south of Brantham the river becomes tidal below Cattawade barrage, after which it opens out to become an estuary near Manningtree, and runs along the southern side of the Shotley Peninsula.

[17] John Nash, who was an official war artist, settled in the Stour valley and is buried at St Andrew's at Wormingford, one of its typically serene small settlements.

Meanwhile, the Trust encourages use of the river by small craft and organises annual events for all age groups and abilities on different parts of it.

No progress was made, due to unrest around the time of the civil war, Spencer's pre-occupation with a similar project on the River Ouse, and his own financial difficulties.

By the late 1600s, John Little and Benjamin Dodd had obtained the rights of the Letters Patent, and later claimed they had spent a lot of money improving the river.

Despite advice from William Cubitt that railways would never offer serious competition in the carriage of heavy goods, the proprietors spent £12,000 on a modernisation programme, involving the construction of towing paths and a cut to bypass a long loop at Wormingford, which included two new locks.

Trade in bricks from the brickworks at Ballingdon Cut and in flour held up for some time, despite railway competition, but in 1892 the proprietors applied for an abandonment order.

The South Essex Waterworks Company rebuilt the locks at Brantham, Flatford, Stratford and Dedham in 1928 at a cost of £20,000,[36] replacing the wooden sides with concrete walls.

[36] There was growing enthusiasm for canal restoration projects in the 1950s, and a group of canoeists from the Chelmsford Boat Club paddled down the lower reaches of the river on 17 October 1954, as part of a campaign to revive interest in the navigation.

[40] The River Stour Action Committee formed a trust in 1967, backed by the Essex Rural Community Council, to focus on restoration of the locks and the navigation.

[42] In 1981, an arm of the Sudbury basin was cleared by the United States Air Force's 819th Civil Engineering Squadron as part of a training exercise.

The trust opened a fund to finance the construction of a new lock at Great Cornard, but a public inquiry to review new bylaws for the navigation proposed that the use of powered boats on the river should be prohibited.

The Trust also paid for the National Rivers Authority to refurbish the gates at Dedham Lock, to make them watertight, and the repairs lasted until they were declared to be unsafe in 2014.

Powered boats are only allowed to use the section of the river near Sudbury from Ballingdon Bridge to Henny Mill, and a speed limit of 4 mph (6.4 km/h) is enforced.

The rest of the once-navigable river from Brundon Mill to Cattawade can be used by canoes, kayaks and other non-powered craft, but have to be portaged around various fixed structures, often located where the locks once were.

The locks at Great Cornard, Stratford St Mary, Dedham and Flatford must be operated by Environment Agency staff, and advance notice of intent to navigate through them must be given.

The craft can be borrowed by the hour, and they also offer a two-day paddle from Sudbury to Cattawade, with transport to and from the start and end points to a campsite in Nayland, which forms the mid-point of the journey.

A new weir containing a fish pass replaced the structure at Judas Gap, and this has resulted in the mill pond at Flatford always being fairly full, even in dry summers.

Water from the River Great Ouse was transferred along the Cut-off Channel to an intake at Blackdyke, from where it flows by gravity to a pumping station at Kennett.

Essex and Suffolk Water can extract 99 million imperial gallons (450 Ml) per day from the Great Ouse, and the Kirtling Brook was too small to cope with this amount.

[72] A comprehensive upgrade of the Stratford St Mary's pumping station was undertaken in 2020, in view of the ageing technology and the fact that it is now licensed to abstract 36 million imperial gallons (164 Ml) per day, more than four times the amount for which it was originally designed.

The pumps were replaced, allowing the volume of water removed from the river to vary between 4.4 million imperial gallons (20 Ml) per day to the full amount of the licence.

A rotating screen supplied by Hydrolux was selected after considering various options, and this was cantilevered off the existing bandscreen building, to minimise disturbance to the river bed.