Prof
Hannah Cloke, an expert in hydrology at the University of Reading, said
"really heavy rain can overwhelm" drainage systems in urban areas as it
often "cannot run away quick enough".
"Water tends to find the lowest pathway - that is why it is so dangerous for cities," she said.
(My emphasis)
Jack
I admit this with a certain embarrassment.
From an early age, I knew that rivers were in valleys – it was the obvious lowest point for rivers to be. It wasn’t until my final year of ‘O’ level geography that I realised that in most cases, it was the rivers that had actually formed the valleys. I suppose I can put some of the blame on poor teaching by ‘Pokey’ Whitehead (so named for an unpleasant personal habit). Even so I got a decent pass at ‘O’ level. Maybe had I understood hydrology rather better in 1954, I would now be the Emeritus Professor Jack Harrison.