Derwent dam - in full flow..from East to West -

The overflowing 'Derwent Reservoir' in the Upper Derwent Valley - Derbyshire,. The River Derwent
flows first through 'Howden Reservoir', then 'Derwent Reservoir' and finally through 'Ladybower Reservoir'. Between them they provide practically all of Derbyshire's water, as well as to a large part of South Yorkshire and as far afield as Nottingham and Leicester 60 miles south. Construction began in 1902... the filling in 1914 and dam overflowed for the first time in 1916. [Wiki]