[12][13] In Medieval Welsh literature, the river was said to be the site of an important battle and the dividing line between ancient Cornwall and Loegria (England).

According to Geoffrey of Monmouth's Historia Regum Britanniae, King Locrinus divorces Queen Gwendolen in favour of his secret lover, Estrildis.

The two armies fight a battle at the river Stour where Locrinus is slain and Gwendolen becomes the ruler of both kingdoms, becoming the first queen regnant of the Kings of the Britons.

In summer, low water level makes the river a diverse and important habitat, supporting many rare plants.

The river flows through a myriad of differing settings and scenery (reed bed, open water, coastal, estuarine, river, streams, lowland heath) and as such is host to species such as the pipistrelle bat, harbour porpoise, great crested newt, medicinal leech, Desmoulin's whorl snail and the starlet sea anemone.

[25] There are many fish that live and use the river, which include; barbel, bream, chub, dace, grayling, perch, pike, roach, rudd, salmon, tench & trout.

[27] The harbour at Christchurch and the lower reaches of the Stour and the Avon are host to a multitude of marinas, boat clubs and landing stages.