There is a fast run-off from the drift covered Keuper marl clay[3] which makes up its catchment area, and heavy rain produces sudden floods; in the absence of replenishing side-streams these subside as quickly as they rise.Crossing Slade Lane at a ford, the 'slade' is the Cole's black silted boggy valley, it begins a journey through the seven kilometres, between Yardley Wood and Small Heath of the Shire Country Park.Due to the construction of the mill pool, Chinn Brook had to be diverted far into the Dingles, flowing at a lesser gradient than the river, until it could join the Cole at the same level.Every year the Tolkien Weekend is held at Sarehole Recreation Ground and Moseley Bog Local Nature Reserve part of the Shire Country Park.[7] The river is bridged by the A41, Warwick Road at Greet, there is no documentary evidence for a ford here,[3] and then continues north, passing under the Grand Union Canal and the Chiltern Main Line railway at Hay Mills close to the Ackers trust outdoor pursuits centre.Passing under Hay Mills bridge it crosses the A45, Coventry Road and from here eleven kilometres of the river and the Cole Valley are protected by the Kingfisher Country Park.The river has the potential to flood during heavy rain and the Stratford Roads' Greet Mill ford shows how treacherous the river could be after heavy rain as the assizes rolls of 1275 record that, Roger Fullard wishing to cross the water with his cart at the mill of Greet, by the flooding water, he and his horses were drowned.
Four Arches Bridge, near Cole Valley Road, Billesley