“I think it is the River Humber Judge.”
‘Fraid not, Togo. It’s on the river Hull. (In fact, as an aside, although it’s often referred to as such, arguably the Humber is not a river at all but a tidal estuary leading from the confluence of the Rivers Ouse and Trent to the sea. Where those two rivers end (at Faxfleet) the Humber begins its short journey to the open sea.)
The barrier is designed to protect the city of Kingston-upon-Hull (to give Hull its proper title) from tidal surges which come up the Humber and flood into the River Hull which goes through the heart of the city. The barrier is a few hundred yards north of the point where the Hull joins the estuary at a place called Myton Bridge. The River Hull is only about 30m wide at that point. The Humber estuary is roughly 3km wide in the same area. (The famous suspension bridge just upstream is 2.2km long). That would be some barrier!!!
I may not know much, but I do know my UK geography :-)