The bridges over the river and the adjacent Exeter Ship Canal were for many years a traffic bottleneck, until the completion of the last section of the M5 motorway, further downstream, in 1977.
The manor of Topsham was granted by King Henry I to Richard de Redvers and became part of his feudal barony of Plympton.
[4] The details of the weir's construction are uncertain: a source of 1290 states that the countess had it built in 1284 and thereby damaged the salmon fishing and prevented boats from reaching Exeter; but a later source claims that her weir was built before 1272, leaving a thirty-foot gap in the centre through which boats could pass, until it was blocked between 1307 and 1377 by her cousin Hugh de Courtenay, 9th Earl of Devon and his son, Hugh de Courtenay, 2nd/10th Earl of Devon.
[6][7] The weirs built by the Earls of Devon across the river prevented ships reaching Exeter, thereby forcing merchants to land goods at their port of Topsham, which therefore prospered.
In 1540, an Act of Parliament was passed to remove the obstructions, but it was found to be impossible to restore the navigation, and work was soon started to build the Exeter Canal to bypass the blocked section of the river.
[10] After the war, accommodation at the navy base was converted into temporary housing for people in Exeter whose homes had been damaged or destroyed.
[15] At the centre of the area is the Countess Wear roundabout, where the old Exeter Bypass meets the crossroads for the Topsham Road.