Notable towns it flows through include Rugby, Warwick, Stratford-upon-Avon, Evesham, Pershore and Tewkesbury, where it joins the Severn.

Improvements to aid navigation began in 1635, and a series of locks and weirs made it possible to reach Stratford, and to within 4 miles (6 km) of Warwick.

Plans to extend the navigable river to provide a link with the Grand Union Canal at either Warwick or Leamington Spa have met with some opposition.

For the first few miles of its length from the village of Welford it forms the border between Northamptonshire and Leicestershire, on this section, it has been dammed to create Stanford Reservoir.

It then flows in a generally west-southwesterly direction, passing through the towns and villages of Rugby, Wolston, (bordering Leamington Spa), Warwick, Stratford-upon-Avon, Welford-on-Avon, Bidford-on-Avon, Evesham and Pershore, before it joins the River Severn at Tewkesbury.

[1] The Avon's tributaries include the Rivers Swift, Leam, Stour, Sowe, Dene, Arrow, Isbourne and Swilgate as well as many minor streams and brooks.

During the Wolstonian glacial period, ice advanced into the Midlands from the north, east and west blocking the flow of the Avon to its former confluence with the Trent.

After about 10,000 years, when the glacier finally retreated, the water was able to cut through the previous watershed and to escape to the southwest, so forming the present day route of the river.

Overnight moorings are available at Stratford-upon-Avon, Luddington, Welford-on-Avon, Barton, Bidford-on-Avon, Harvington, Offenham, Evesham, Craycombe, Wyre, Pershore, Defford, Comberton, Birlingham, Eckington, Strensham and Tewkesbury.

The river forms part of the Avon Ring, a circular cruising route which is 109 miles (175 km) long, and includes 129 locks.

The only objections were from Sir William Russell, who owned Strensham mill, and whose grievance was about land purchase, rather than the navigation works.

[9] Meanwhile, the Upper Avon Navigation between Stratford and Evesham was owned by relatives of Lord Windsor, who had died in 1758, and its condition gradually deteriorated.

The arrival of the Oxford, Worcester and Wolverhampton Railway at Stratford sealed its fate, and when the company failed to sell the navigation to local landowners for £150, they effectively abandoned it in 1857.

The Worcester and Birmingham Canal renewed their lease in 1851 for a further 21 years, but traffic was severely hit by the opening of a railway link from Ashchurch to Evesham in 1864.

[10] The first moves to return the waterway to a navigable condition occurred in March 1949, when the Evesham Journal published an article on its history and decline.

[14] An anonymous benefactor was about to give £80,000 in 1963 towards the restoration on the Upper Avon, while a donation of £5,000 enabled Evesham lock to be rebuilt and opened on 11 June 1964.

Negotiation with the Severn River Authority led to an agreement that such works could be constructed, which was eventually formalised when a private Bill[15] was put before parliament, which became the Upper Avon Navigation Act 1972.

The estimated cost for the complete restoration was £250,000, all of which was raised by public subscriptions, with the exception of a grant for £25,000 from the Department of the Environment, which was made at the time of the phase 1 opening.

This was first considered by the Severn Trent Water Authority in 1974, who conducted a survey, the cost of which was partly funded by the Inland Waterways Association.

Reasons for the water quality being less than good include run off from agricultural land and discharge from sewage treatment plants, both private and public, while the lower river is also affected by physical modification of the channel.

Like most rivers in the UK, the chemical status changed from good to fail in 2019, due to the presence of polybrominated diphenyl ethers (PBDE), perfluorooctane sulphonate (PFOS) and mercury compounds, none of which had previously been included in the assessment.

Craig was supported by a four man land and boat crew consisting of Robert Stringer, Bob Bain, Joe Bawdon and Phil Leibrandt.

Despite being an ex-competitive pool swimmer, Craig had never taken part in open water swimming previously and the crew had never embarked on any similar challenges.

The team set off from Alveston Weir in Stratford-Upon-Avon at 20:00 on Friday 16 July 2021 and swam through the day and night to complete the 47.1 mile swim.