The river is 16.4 kilometres (10.2 mi) long from the source to the outfall on Heacham beach, which discharges into The Wash at low tide.

[2] From its source at a pond near Bircham Newton the river flows towards Fring where it is crossed by Peddars Way and then runs across open countryside in a north westerly direction.

After the mill the river passes under the A149 coast road and then skirts around the northern side of the village of Heacham.

After the lake the river goes north for a couple of hundred feet before turning west again crossing low-level meadows.

The river ends up against the tidal flaps at South Beach between Snettisham and Heacham, where it fills a series of pools that run parallel to the coast.