Rhine discharge at Basel hits record low for early October.

October 4, 2026

On 3 October 2026, the Rhine at Basel-Kleinhüningen recorded an exceptionally low daily discharge of 365 m³/s, placing it among the most severe low-flow events since 2020. Such low water levels raise transport costs, degrade water quality, restrict cooling-water use, and stress water supply, groundwater, and river ecosystems.

On 3 October 2026, the average daily discharge at the Rhine River’s Basel-Kleinhüningen station was lower than 1% of all measured daily discharges since 2020. The daily mean was 365 m³/s, with a minimum of 262 m³/s and a maximum of 470 m³/s. These values are exceptionally low for the time of year. The maximum discharge on 3 October ranked 18th over the last 30 days, 3rd among all October days since 2020, and also 3rd among all days since 2020.

Over the past 30 days, the highest discharge was 576 m³/s on 8 September 2026, while the lowest was 188 m³/s on 22 September 2026. Table 2 lists the months with the lowest flow conditions since 2020; the current October 2026 flow is included in that table, alongside September 2026, August 2026, August 2022, and July 2026. The current low flow is therefore consistent with the most severe low-flow months recorded in the available period.


Low water levels on the Rhine have consequences that reach well beyond the river itself. Cargo vessels have to reduce their load to stay clear of the riverbed, so more trips are needed to move the same volume and transport costs rise sharply, with the effect passed on to industries that depend on the waterway for coal, oil products, chemicals and grain. The shallower water also heats up faster in summer. Warmer water encourages bacterial growth, which can produce noticeable odors, and it holds less dissolved oxygen. The combination of higher temperatures, lower oxygen and more concentrated pollutants degrades water quality and can lead to fish kills. Swimming is generally discouraged under these conditions because of the higher bacterial load. Further effects include restrictions on power plants and industrial sites that draw river water for cooling, since they may no longer discharge warmed water without exceeding temperature limits, reduced dilution of treated wastewater, pressure on water supply and irrigation in the surrounding area, and falling groundwater levels along the river that affect riparian vegetation and wells.



Table 1: Comparison of Rhine River Discharge from 2026-10-03 and historic October statistics
metric '2026-10-03'::date Historic
Average discharge 365.5 899.7
Maximum discharge 469.6 2194.0
Minimum discharge 262.1 262.1


Table 2: The five months since 2020 with the lowest daily flow
Month Min Avg Flow [m3/s]
09.2026 361.2
10.2026 365.5
08.2026 413.0
08.2022 435.9
07.2026 442.1

Figure 1: Rhine River Discharge [m³/s] over the Past 30 Days

Data source: Rhein Wasserstand, Pegel und Abfluss
Additional resources: Data provider: Federal Office for then Environment (FOEN), Hydrological Data and Forcasts

🤖 This text was generated with the assistance of AI. All quantitative statements are derived directly from the dataset listed under Data Source.