In 2023, we set out to explore the relationship of the site to the river by extending our largest trench north.
We found what we first thought to be a boundary ditch, but its shape and depth soon showed it to be a mill leat – our first evidence for a watermill.
The picture above shows the current extent of the 2025 excavation; we have a little way to go. The leat supplying water to the mill is in the foreground (bottom of the picture) and beyond (middle of the picture) is what we suspect is the actual slot for the wheel. Both horizontal and vertical wheels were in use in Early Medieval England. If we are right about the wheel slot, its narrowness (approx. 1m) means that the Cookham wheel could only have been a vertical one.
Only half a dozen Anglo-Saxon watermills have been excavated. This leat is a particularly good example as, unusually, one can see the full depth – often the top levels have been removed by later activity, or it has not been possible for those excavating to reach the bottom.
Some timber revetments and the posts supporting them, have survived at the very bottom of the leat. We are hoping that one of them will be a big enough to allow dating through dendrochronology (tree ring dating).