The Rhône is infamous for its strong current when the river carries large quantities of water: current speeds up to 10 kilometres per hour (6 mph) are sometimes reached, particularly in the stretch below the last lock at Vallabrègues and in the relatively narrow first diversion canal south of Lyon. The 12 locks are operated daily from 5:00 a.m. until 9:00 p.m. All operation is centrally controlled from one control centre at Châteauneuf. Commercial barges may navigate during the night hours by authorisation.