| Hermance | |
| Pushpin Map: | France#France Auvergne-Rhône-Alpes |
| Subdivision Type1: | Countries |
| Subdivision Name1: | France and Switzerland |
| Mouth: | Lake Geneva |
The Hermance (in French pronounced as /ɛʁmɑ̃s/) is a river in France and Switzerland, that discharges into Lake Geneva. It rises near Loisin in Haute-Savoie, France, at elevation.[1] In its lower half, downstream from Veigy, it marks the Swiss-French border. It flows into Lake Geneva between the villages Hermance (Switzerland) and Chens-sur-Léman (France), at elevation.[1] Its total length is (according to the Sandre database), of which 6.5 kilometres on the border. Its catchment area is, of which 37 km2 in France.[1]
Flood control and other river maintenance issues are regulated under the 1959 Hermance River Agreement.[2]