After a winter with little precipitation, this spring has likewise brought scant rainfall. In addition to effects on vegetation, the dryness is also evident in hydropower. According to the nationwide electricity group Verbund, this spring ranks among the five driest in the past 100 years. The power sector, however, is reassuring: “We do not currently see cause for alarm,” a spokesperson for Austria’s Energy Association (Oesterreichs Energie) told APA.
Verbund’s hydropower generation so far this year amounts to 80 percent of the long‑term average. “That is within the normal range of fluctuation but is nonetheless one of the five driest springs in 100 years,” a company spokesman wrote in response to an APA inquiry. Less water does not automatically mean proportionally less electricity generation, because the head height at each plant also matters. Lower river flows reduce downstream water levels, “which increases the vertical drop between the upstream and downstream levels—and thus the head height. This helps mitigate the loss in energy output,” Verbund explained.
Climate Change Brings More Extreme Weather
Overall, a shift in generation patterns is observable. “Man‑made global warming is bringing more frequent extremes like droughts and heavy rains,” the electricity group noted. At present, shortfalls in hydropower are covered by pumped‑storage plants, gas‑fired power stations, and electricity imports. A stronger expansion of wind power could reduce springtime import dependence in future years.
Oesterreichs Energie also sees no reason for concern, emphasizing that river flows follow natural fluctuations. According to the energy regulator E‑Control, the generation coefficient of run‑of‑river plants was 0.98 in January and 0.86 in February, where 1.0 represents the long‐term average. Data for March are not yet available. Austria’s Energy Association likewise points to seasonal shifts in precipitation and river flows, noting that overall water volumes have remained stable in recent years despite climate‑driven extremes.
Regionally Varied Flows
Vienna Energie’s hydropower output is also affected by the dry spell. “We cannot make a general statement because our hydro plants are spread across very different locations in Austria,” a spokesperson said. Some plants are barely below last year’s output, while others show larger swings. Last year (2024) was an exceptionally good year for hydropower.
The low winter 2024/25 precipitation has similarly impacted Lower Austria’s hydropower. Compared with the excellent water flows of 2023/24, “generation in some months was up to 50 percent below the expected amount,” reported the publicly listed utility EVN. For EVN, drought poses not only a power‐generation challenge but also concerns for drinking‐water supply. “Currently, our wellfields are holding stable water levels, and we feel well prepared for summer,” the company emphasized.
Balanced by Storage and Imports
The state‐owned Tyrolean utility Tiwag, which operates hydro plants across the province, described “below‐average flows, especially on the Inn River in the lower Inn valley.” There, power output is “below long‐term averages.” Conditions in East Tyrol are closer to normal. In total, available inflows are about 10 percent below historic norms, which immediately affects run‐of‐river generation. When hydro plants produce less, the shortfall must be offset by extra output from pumped‐storage facilities or by imports from the European grid, Tiwag said, noting that “fluctuations in generation due to changing flows are not unusual.”
In Vorarlberg, the lack of rain since last autumn has led to very low water levels in all waterways and Lake Constance. The regional supplier illwerke vkw estimates a 20 percent drop in hydropower output versus an average year—but says this remains within normal long‐term variation. Supply security is unaffected, as electricity can be purchased on the market if needed.
Snowmelt Will Help
In Salzburg, water flows—and thus hydropower output—are about one‑fifth below plan so far this year, Salzburg AG reported. Recent mountain snowfall should boost flows once the melt begins. The Salzach River’s flow is now at its lowest since 1990. Salzburg AG compensated with storage‐based generation through mid‑March but has since had to buy power on the market. Statistically, flows remain within long‐term bounds, albeit at the low end; the persistence of the drought suggests a climate change influence.
Upper Austria’s Energie AG sees generation slightly down—around 10 percent below the long‑term average—but within natural variability. Supply security is assured. “In the long run, total water volumes haven’t shifted significantly—only the timing has changed,” its spokesperson said.
In Carinthia, drought has had little effect so far: “Flows in Kelag’s area are currently at 99 percent of average,” said Kelag spokesperson Josef Stocker. However, scant mountain snow this winter means less meltwater in May and June, which will reduce hydropower generation unless a wet spring compensates.
