The historic heatwave of recent days led to new peak values in drinking water consumption for regional supplier Hessenwasser. Last Thursday, the company delivered nearly 441,000 cubic meters of drinking water, more than ever before in a single day. And on Saturday, despite the start of school holidays, more than 427,000 cubic meters were consumed by the roughly two million residents of the Rhine-Main region supplied by Hessenwasser. Consumption only dropped slightly on Sunday. The previous record was 426,000 cubic meters on a summer day in 2019.
While Hessenwasser was able to provide these water volumes without issue, bottlenecks in water supply still occurred in the Rhine-Main region. “For us as upstream suppliers, covering peak demand is not a problem,” said Hessenwasser CEO Elisabeth Jreisat. The real challenge during such hot weather lies in the technical capacities of waterworks, reservoirs, pumping stations, and transport pipelines. Residents of the city of Offenbach and parts of the Offenbach district felt this over the past days: over the weekend, Offenbach declared a water emergency.
It was an exceptional situation – but according to those responsible, it could recur due to the consequences of climate change. Because of the heatwave, consumption in the affected areas had risen to a record high, and drinking water supply in Offenbach and large parts of the district could no longer be guaranteed. The situation eased over the weekend. Offenbach Mayor Felix Schwenke (SPD) cited the start of summer holidays and the travel wave as reasons, and appeals to save water apparently also had an effect. Additionally, by purchasing water from other suppliers, such as Hessenwasser, they were able to meet demand and refill reservoirs.
Responsible in this case is the Zweckverband Wasserversorgung Stadt und Kreis Offenbach (ZWO), a joint venture of the city and the district. Its supply area extends beyond the city and district of Offenbach, including the Hanau districts of Steinheim and Klein-Auheim. However, the Hanau municipal utilities plan to take over its water supply in the future. The Zweckverband Wasserversorgung Offenbach operates more than 100 wells in the “Hanau-Seligenstädter Senke,” where groundwater flows toward the Main River.
By the end of last week, the wells were no longer sufficient, and water extraction reached its capacity limit. Therefore, short-term purchases from other suppliers had to be increased to refill the elevated tanks at night. The elevated tanks serve as storage and stabilize the network during peak times, i.e., when particularly large amounts of water are consumed simultaneously.
Source: www.faz.net
