Recent thunderstorms have had no effect on low water levels across Switzerland. The prolonged drought means many rivers still have extremely little water.
Although rainfall of up to 50 litres per square metre was recorded locally recently, especially in the mountains, this resulted in only short-term increases in run-off in the affected regions, the Federal Office for the Environment said on Monday.
River levels are particularly low in the Central Plateau and the Jura in northwestern Switzerland. In the high alpine, glaciated catchment areas, the water outflows are either normal for the season or below average.
Exceptionally low water levels are found on Lake Lucerne, Lake Zug, Lake Zurich, Lake Constance and the Walensee. Only Lake Thun, Lake Lugano and the lakes around the Jura have normal levels for this time of year.
In addition, the persistent summer temperatures mean water temperatures of many rivers are still above average.
The weather is set to remain mostly dry for the next few days. The water levels of most Swiss waters will continue to decline accordingly or remain at low levels, the environment office predicts.