Rhine Flow Hits Record Low Since 2020

July 30, 2026

On 29 July 2026, the Rhine at Basel recorded an exceptionally low discharge, lower than 99% of all daily flows since 2020. These low water levels have far-reaching consequences, including sharply higher transport costs, degraded water quality, restrictions on industrial cooling, and pressure on water supply and groundwater.

On 29 July 2026, the average daily discharge of the Rhine at Basel-Kleinhüningen was lower than 1 % of all daily discharges measured since 2020. The flow ranged from a minimum of 359 m³/s to a maximum of 554 m³/s, with a mean of 472 m³/s. These values are notably low: the maximum discharge on this day ranked 25th out of the last 30 days, 6th among all July days since 2020, and is among the very lowest when compared with all days in the record since 2020.

Over the past 30 days, the highest discharge was 1068 m³/s on 2 July 2026, while the lowest was 343 m³/s on 27 July 2026. Table 2 lists the months with the lowest flow conditions since 2020; July 2026 already appears in that table with a minimum average flow of 456 m³/s, and the current flow is even lower than that value.


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 2026-07-29 and historic July statistics
metric '2026-07-29'::date Historic
Average discharge 471.8 1172.8
Maximum discharge 554.3 3729.4
Minimum discharge 359.2 219.7


Table 2: The five months since 2020 with the lowest daily flow
Month Min Avg Flow [m3/s]
08.2022 435.9
07.2026 456.4
04.2025 470.4
03.2023 471.4
03.2022 476.6

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.