When Lakes Run Low: Transboundary Water Governance and Drought

In this piece published on 18 September 2026, our Senior Science Policy Interface Manager, Laura Turley (University of Geneva, Institute of Environmental Sciences), reflects on how Switzerland's exceptional summer 2026 drought exposed the fragility of transboundary water governance in Europe. Despite the country's reputation as Europe's "water tower", the season saw Lake Zurich fall to its lowest level since records began in 1951, Lake Constance drop well below seasonal norms, and Lake Maggiore reach a critical threshold that forced an emergency meeting of the Italian-Swiss regulatory body and prompted increased outflows from Lake Lugano to protect rice-growing districts downstream around Novara, Lomellina and Milan.

Turley argues that these events show how quickly upstream stress cascades across borders, turning a hydrological problem into a diplomatic one. Existing treaties and joint commissions were largely designed under more stable climatic conditions and rely heavily on "best-effort" cooperation rather than binding drought-response mechanisms. As hydrological extremes interact with pollution pressures and diverging national interests (particularly at the EU / non-EU interface), the legal architecture governing shared lakes is being tested in ways its drafters never anticipated.

The article calls for strengthening the adaptive capacity of transboundary agreements — through better data-sharing, coordinated low-flow protocols, and clearer allocation rules for drought years — so that Alpine lakes and their downstream users can weather an increasingly dry future together rather than in competition.

🔗 Read the full article: When the lakes run low: transboundary water governance and drought