Persistent heat wave in Switzerland impacting water levels in rivers, lakes

The Swiss Federal Office for the Environment (FOEN) reported Monday that the protracted heat wave and drought affecting Switzerland has engendered below average water levels in many of the confederation's lakes and rivers.

The persistent heat and lack of rain has meant that both water levels and flow rates are below the seasonal average, with a number of small and medium-sized watercourses in the Jura and Tessin cantons positing critically low water levels, while some are partially dried up.

FOEN indicated that larger rivers have not been spared by the heat wave, with the Aar, Limmat, Reuss and Rhin rivers currently displaying weaker than usual flow rates.

Water levels in many of the country's lakes are also below average and are expected to continue dropping over the coming days.

According to FOEN, this directly impacts aquatic life, as high water temperatures can engender stress and even death for fish, while the risk of contracting illnesses also increases.

High temperatures have decreased ice levels in some of the confederation's glaciers, amid estimations that this year will be particularly hard on Switzerland's glacial masses.

Between 6 and 8 cm of ice thickness have been lost every day recently on the Aletsch and Rhone glaciers, with predictions indicating that melting will continue over the next few weeks.

With the month of July the hottest on record in Switzerland since statistics were first compiled in 1864, especially in Southern Alpine regions and in Engadin, Valais and Romandie areas, FOEN predicts that this year's summer season will be the second hottest in 150 years.

The agency reported that a relatively long period of heavy rainfall is needed to replenish groundwater reserves and to normalize river flow rates. Endit