[Kizzy]

I was thinking dredging, or the lack of leading to higher river levels initially.

In Keswick, new £6 million flood defences built to withstand 2009 highs of 15.2 feet were overwhelmed when the River Greta surged to 17.4 feet.
The Mayor of Keswick Paul Titley said: “The flood defences were designed for a one in 100 year event and since it's six years since we had the last one, we were sort of surprised that we got one so soon.”

Locals complained that lack of dredging had made the problem worse.
“There was erection of expensive and ineffective glass panels on the wall next to the River Greta in Keswick, but absolutely no dredging of the gravel that has raised the river bed considerably over the last decade or so,” said Philip Walling.

http://www.telegraph.co.uk/news/weat...to-misery.html