River Risle

Risle
Ponor of the Risle near La Ferrière-sur-Risle.
Country	France
Basin features
Main source	Normandy
River mouth	Seine 49°26′19″N 0°22′21″E / 49.43861°N 0.37250°E / 49.43861; 0.37250 (Seine-Risle)Coordinates: 49°26′19″N 0°22′21″E / 49.43861°N 0.37250°E / 49.43861; 0.37250 (Seine-Risle)
Progression	Seine→ English Channel
Basin size	2,310 km2 (890 sq mi)
Physical characteristics
Length	145 km (90 mi)
Discharge	Average rate: 14 m3/s (490 cu ft/s)

The Risle (less common: Rille) is a 144 km (89 mi) long river in Normandy, left tributary of the Seine.

The river begins in the Orne department west of L'Aigle, crosses the western part of the department of Eure flowing from south to north and out into the estuary of the Seine on the left bank near Berville-sur-Mer. Its upper valley is part of the Pays d'Ouche, its lower valley separates the regions of the Lieuvin and Roumois.

The Risle is regarded as a coastal river. Fishing is common downstream at Pont-Audemer.

On July 30, 2012 the Risle vanished in a ponor between La Ferrière-sur-Risle and La Houssaye. It runs underground for 8 kilometres.

Its only major tributary is the Charentonne. The Risle flows through the following departments and communes: