Isère (river)

Isère
The Isère in the center of Grenoble.
Drainage basin of the Rhône (the Isère flows through Grenoble in the center of the map).
Country	France
Region	Departments of Drôme, Isère, and Savoie in the Rhône-Alpes region
Basin
Main source	Sources de l'Isère Glacier, Grande Aiguille Rousse, Graian Alps ±2,900 m (9,500 ft) 45°26′45″N 7°5′47″E / 45.44583°N 7.09639°E / 45.44583; 7.09639
River mouth	Rhône ±110 m (360 ft) 44°58′56″N 4°51′8″E / 44.98222°N 4.85222°E / 44.98222; 4.85222Coordinates: 44°58′56″N 4°51′8″E / 44.98222°N 4.85222°E / 44.98222; 4.85222
Progression	Rhône→ Mediterranean Sea
Basin size	11,890 km2 (4,590 sq mi)
Physical characteristics
Length	286 km (178 mi)
Discharge	Average rate: 329 m3/s (11,600 cu ft/s)
Features
Tributaries	Left: Arc, Drac Right: Arly
Sources	Sandre, Géoportail, Banque Hydro (), Symbhi ()

The Isère (pronounced: [i.zɛʁ]) is a river in the Rhône-Alpes region of southeastern France. Its source, a glacier known as the Sources de l'Isère, lies in the Vanoise National Park in the Graian Alps of Savoie, near the ski resort Val d'Isère on the border with Italy. An important left-bank tributary of the Rhône, the Isère merges with it a few kilometers north of Valence.

Many riverside communes have incorporated the Isère's name into their own, for example, Sainte-Hélène-sur-Isère and Romans-sur-Isère. The department of Isère is likewise named after the river.

The name Isère was first recorded under the form Isara, which means "the impetuous one, the swift one." Not originally a Celtic word, it was very likely assimilated by the Celts in ancient times. This word is related to the Indo-European *isərós, meaning "impetuous, quick, vigorous," which is similar to the Sanskrit isiráh with the same definition. It was probably based on the reconstructed Indo-European root *eis(ə) (and not *is), which incidentally has not been found in the Celtic languages of the British Isles.