Switzerland's Water Tower Runs Dry: Lake Zurich Hits Record Low as Drought Enters Sixth Month
Lake Zurich has fallen to its lowest level since measurements began in 1951. The Untersee has broken a record that stood since 1949. Rivers are reduced to trickles, shipping is restricted, and municipalities across the country are rationing water.
Switzerland is running out of water. The country that markets itself as Europe's water tower is facing a drought unmatched in decades, and the numbers are staggering.
Lake Zurich, the sixth-largest lake in the country, has fallen to its lowest level since measurements began in 1951. The federal measuring station at Zurichhorn recorded a water level of just 404.45 meters above sea level on August 19, falling below the previous record of 405.46 meters set in 1952. The level is 63 centimeters below the September average, and it continues to drop.
The Untersee, the western part of Lake Constance, has broken an even older record. On September 23, its level fell four centimeters below the lowest level ever recorded, which dated back to January 14, 1949 — measurements at that point have been taken since 1885. Lake Walen has also hit a September record low, and Lake Constance has been at its lowest ever recorded levels for the season since the end of June.
The drought is not a summer phenomenon. It began in spring and has persisted through autumn. Between April 1 and July 31, around one-fifth of Switzerland's monitoring stations recorded their lowest water levels for that period since measurements began. In July, water scarcity affected 99 percent of Swiss territory, and the drought risk remained at the highest level across the country as of August 10.
The federal government's own documentation of a severe drought scenario paints a grim picture of what is unfolding. River flows are reduced, and run-of-river power plants are producing up to 25 percent less electricity. Reservoir power plants are generating up to 30 percent less due to low reservoir levels. Nuclear power plants, data centers, food processing operations, and pharmaceutical infrastructure with large thermal needs are being forced to reduce output because they can draw less water or discharge less heat into the waterways. The Beznau nuclear power station had to reduce output from June onwards and at times shut down completely due to high water temperatures in the Aare.
The Rhine, Switzerland's most important waterway for imports, is severely affected. Larger cargo ships can only navigate with heavily reduced loads, and the shift to rail or road transport offers only a partial solution. Delays are occurring in fertilizer, animal feed, oilseeds, grain, and mineral oil deliveries. Fuel transport has become more expensive, and residents in Basel have reported filling their tanks for 100 francs instead of the usual 80.
Agriculture is in crisis. Due to declining grassland yields, farmers are facing additional costs for buying high-priced roughage. Feed and drinking water shortages for livestock, especially in summer grazing areas, are forcing cattle to be sent for slaughter in significantly higher numbers. In the worst-affected regions, agricultural production is partially collapsing, and many farms are facing existential threats.
Municipalities have been forced to act. More than 194 communities have called on their residents to save water, and at least 151 have imposed bans on specific water uses, with fines of up to 2,000 francs. In Wittnau in the canton of Aargau, the three local springs are delivering only 231 liters per minute — compared to the normal 500 to 600 liters for this time of year. The village needs around 200 liters per minute during the day. The community has turned off its fountains, the fire brigade has stopped water-intensive exercises, and residents are banned from filling pools or watering lawns. Since July, the municipality can issue fines.
In the canton of St. Gallen, the population, agriculture, and businesses have been called upon to use water carefully. Water withdrawals from surface waters are being progressively banned, and access to particularly sensitive water sections is temporarily prohibited to protect fish and aquatic life.
The canton of Thurgau reports that its water bodies are at historically low levels, with some having dried up completely. The situation is expected to worsen in the coming weeks.
Lake Zurich's low level has had immediate consequences for shipping. The Zurich Lake Shipping Company has been forced to close four stations, including Küsnacht Heslibach, Bellevue, and Limmatquai, because the height difference between ship and dock has become too great for safe boarding. The Obersee ferry suspended operations entirely. The Limmat boat round trip was cancelled. The company is using larger ships with different hull designs to manage the remaining routes.
The Zurich Lake Ferry between Horgen and Meilen has informed customers of restrictions on vehicle loading due to the "extraordinarily low" water level, barring crossings by heavy trucks and several other vehicle types.
In October, the Federal Office for the Environment will reduce the outflow from Lake Zurich from 30 to 20 cubic meters per second to slow the further decline of the lake level and limit restrictions for shipping, the lake ferry, and the rescue service. Less water flowing into the Limmat will affect the ecosystem and hydropower production, with negative consequences for fish and other aquatic life.
The drought is the result of a second consecutive winter with little snow and intense summer heatwaves. The summer of 2026 was the hottest since records began in 1864. The canton of St. Gallen notes that the current drought surpasses those of 2003 and 2018.
The federal government has acknowledged the need for action. Parliament has called for a national water strategy, expected by the end of 2027. A working group on drought has recommended five packages of measures, including regional water resource planning, improved data availability, intercantonal coordination, knowledge exchange, and secure financing options. But the strategy is not yet in place, and the water continues to recede.
For now, Switzerland is confronting a reality it has long denied: even the water tower of Europe can run dry. The lakes are at record lows. The rivers are shrinking. The farms are struggling. And the rain, when it comes, may not be enough to refill what has been lost. The drought has entered its sixth month. And winter, with its promise of snow, is still a long way off.
Written by Freya Stensrud freya.stensrud@alpineweekly.com