Vorarlberg rivers recorded lowest flows in a decade

Rivers and streams in Vorarlberg recorded their lowest flows in at least a decade during the latest measurement period, according to data reported by ORF. Treated wastewater kept some streams from drying up, while spring water temperatures continued to rise.

Annual runoff was the lowest since 2016 at 16 of 17 monitoring stations, according to state data. The Bregenzer Ach at Kennelbach and the Dornbirner Ach at Lauterach each carried just over half their usual volume. The figures for this year are provisional.

The measurement period, also called the water year, generally runs from November 1 to October 31 rather than following the calendar year.

State councillor Christian Gantner said in a response to a parliamentary inquiry by the Greens that treated wastewater prevented some streams from drying out completely. Monitoring stations also recorded higher water temperatures, more nutrients and oxygen deficits. The data did not identify which streams were affected.

State data covering the past decade also show that spring water is warming. Several monitored springs recorded their highest temperatures of the decade this year and last year. At the Widum-Bach spring, the temperature has risen by half a degree since 2019. Higher water temperatures can put water quality at risk.

The state is also contributing funding to two water projects on Lake Constance. It is providing just under 90,000 euros to maintain the shipping channel in Fußacher Bay and a further 70,000 euros to repair the flood-protection dam at the pumping station in Höchst. The projects aim to secure shipping and improve flood protection.