Heat and drought damage roads across Dornbirn

Long-lasting heat and drought have damaged road surfaces in Vorarlberg, with some sections in the city of Dornbirn sinking by up to 20 centimetres, ORF reported.

The most serious damage is in the Rohrbach district and on Dr Anton Schneider Street. The depressions have become dangerous for buses, according to Gernot Spiegel, head of Dornbirn’s civil engineering office. Both regional and city buses have already scraped the road surface, he said.

The damage was not caused directly by heat affecting the asphalt. Instead, the drought has lowered the groundwater table. In the affected area, groundwater is around three metres below its normal level, Spiegel said. In western Dornbirn’s lower-lying area, it is currently about one metre lower.

The removal of water has disturbed the soil balance, causing the ground to shrink or decompose and the road surface to gradually sink.

Large trees along the roads also contribute to water loss. A mature tree uses around 300 to 500 litres of water a day and releases it during the day through convection, lowering temperatures by up to five degrees. However, Dornbirn gives priority to the trees over the roads, Spiegel said.

Localised road repairs are under way and are expected to cost between 80,000 and 100,000 euros. The Rohrbachstraße has suffered so much damage that it will require a complete renovation, scheduled for 2028 under Dornbirn’s road construction programme.