RIVER FOSS

The 'River Foss' is an improved river in North Yorkshire, England, and a tributary of the River Ouse. It rises at Oulston reservoir at Yearsley and runs south through the Vale of York to York itself, which stands on the confluence between the Ouse and the Foss. Improvement works were promoted by Acts of Parliament in 1793 and 1801 which sought to make the Foss navigable as far as Sheriff Hutton. It is navigable for just over a mile from Monks Bridge to Blue Bridge in the centre of York where it joins the Ouse.
The 'Foss Barrier' is built across the river near its mouth. When closed, it prevents floodwater from the much larger Ouse flowing ''up'' the Foss and flooding those parts of York in its vicinity. Water flowing ''down'' the Foss can be pumped over the top of the barrier and into the Ouse.