Which river is the primary outflow of Lake Geneva?

The primary outflow of Lake Geneva is the Rhône.

The Rhône enters Lake Geneva from the east after descending through Switzerland’s Valais region, then leaves at the lake’s southwestern end in the city of Geneva. The river therefore both feeds and drains the lake, although the lake moderates its flow and allows much of the incoming sediment to settle.

Lake Geneva is shared by Switzerland and France and is the largest lake along the Rhône’s course. Its French name, Lac Léman, is widely used locally and historically; “Lake Geneva” is the usual English name. The lake’s western outlet is controlled near Geneva before the Rhône continues into France.

The Rhône is easy to confuse with the Rhine or Aare because all are major rivers associated with Switzerland. The Rhine flows north toward the North Sea, while the Aare is a major Swiss tributary of the Rhine. After leaving Lake Geneva, the Rhône continues southwest through France and eventually reaches the Mediterranean Sea near the Rhône delta.