P.S. The caption on the original photo is slightly wrong. The Wytham/Seacourt Stream (the ‘old’ Thames) leaves ‘The Thames’ at this point and the main river flow diverts off towards King’s Weir.
As can be seen below, the current depth at King’s Lock (Weir) is 0.11 meters.
If the drop from river to stream at Wytham Weir/Hagley Pool is larger than that (it will be) Then Wytham Weir controls the amount of water that goes to King’s lock and thence down towards Oxford.