The name actually comes from Thetford[7] rather than the other way around as Thetford was such an important settlement during the Anglo Saxon period from which the name is derived. The other most notable settlement along the Thet is East Harling[8] where the river has been forded for many centuries.[9] Now a brick and concrete bridge carries the B1111 road over the river. Beneath the bridge is a weir and a widened section of river with a gravel bed (elsewhere the riverbed is predominantly mud). Downstream the river passes over another weir at Bridgham where another bridge crosses it and then through the Shadwell Estate. Here it splits into two channels, reconverges and passes a large artificial lake.[10] When the river reaches Thetford it curves south then west again, meeting the Little Ouse just west of Butten Island in the centre of the town.
In the upper reaches of the Thet, there are a series of lakes including flooded gravel pits. These are situated at Snetterton[11] in a linear pattern along the floodplain and also near Attleborough.[12] All of these lakes are on private land and used for fishing.[13]
