Spring balance 2025: Ruhrverband records driest March in over 30 years

The meteorological spring of 2025 was too dry in the Ruhr catchment area. This is according to the Ruhrverband's analyses. With a total of 150 millimetres of precipitation, 33% less fell than the average for the years 1927 to 2024. March was particularly dry with only 14 millimetres of precipitation on average in the area, which corresponds to a drop of 82% compared to the usual amount for this month. Since the Ruhrverband began recording precipitation 98 years ago, March has only ever been drier three times, most recently in 1993. May was also drier than usual (minus 17 %), while April was almost average (plus 3 %). With a plus of 1.0 degrees compared to the reference period 1991 to 2020, spring 2025 was also too warm.

As February had already been very dry with a minus of 74 %, the Villigst gauge was already obliged to receive water from the reservoirs from March, which was an unusually early point in time. This totalled 48 days for the entire spring in Villigst and 14 days at the estuary (where the subsidy was only necessary from April). At both control cross-sections, this was the third-highest number of days requiring a subsidy that the Ruhrverband has recorded in one spring since the introduction of the statutory minimum discharges in 1990.

Thanks to the subsidy payments from the Ruhrverband's reservoirs, the minimum discharges in the Ruhr were met at all times in spring 2025. Due to the water releases required for this, the total reservoir level was already below the long-term average for the time of year from 9 March and then for the rest of the spring; on 31 May, the shortfall compared to the usual level was just under 5 %. Compared to the reservoir contents of the previous year, when the spring was twice as wet, there are currently 35.3 million cubic metres less water stored in the reservoirs. This roughly corresponds to the combined capacity of the Verse and Fürwigge dams. Nevertheless, the dam system is well positioned for further dry phases with an obligation to provide additional water in the coming months. At the same time, there is sufficient free space to retain water in the event of heavy rainfall and thus minimise flood peaks in downstream areas.