150 km long, the Risle has its source in the department of Orn and flows into the Seine, upstream of Honfleur. Its catchment area, with a reach of nearly 2,300 km², is located mainly in the department of Eure.
The Risle Valley is a wide, flat-bottomed valley, mostly occupied by bocage meadows (mixed woodland and pasture). It has tourist assets, land and water, which highlight its environmental richness and are the subject of numerous inventory or protection zoning, such as the RAMSAR site of the Marais Vernier.
The town of Pont-Audemer, halfway between Caen and Rouen and 20 km from the English Channel, has a strong link with the Risle due to the presence of canals in its old centre, which have earned it the nickname of “small Norman Venice”. In the main urban center downstream, its industrial past is still visible, as evidenced by the old COSTIL tannery, now abandoned.