When I lived in Bath, many years ago, some of the older residents lauded the name of one Frank Greenhalgh (apparently pronounced Greenhouse) who, as City Civil Engineer, had devised a system of weir and sluices on the River Avon which saved them from frequent flooding. It has been very wet recently and the river is high. However, by opening this massive sluice gate near Pulteney Bridge, citizens downstream have not had to take to their rowing boats as they did previously.