Photos taken by Sudbury photographer Tim Ranson show the incredible drop in water level on the River Stour.
The level dropped suddenly after a control gate was blocked open at Cornard weir.
The main river channel has shrunk while cut-offs have been left almost completely dry, as seen at the cut off the former Granary.
The Environment Agency (EA) is working to fix the problem, saying they hope to have it working by the end of the weekend.
Meanwhile EA workers have been desperately trying to save thousands of fish that have been left in the increasingly shallow pools, wading in the mud and catching them in nets before relocating them in deeper water.