Photography of sediment near the bank (left bank) of the bottom of the downstream portion of the Upper-Deûle (Lille / Lambersart area) in northern France. This photo was made on a day when channeled Deûle was unusually clear (no barge traffic or sluice opening, November 11, 2014). And currents generated by contrecourants hydropeaking and propeller wash barges dug sediment so differentiated, after building work on banks.