On 4 August 2026, the average daily discharge of the Rhine at Basel-Kleinhüningen was 457 m³/s, which is lower than 1 % of all daily averages recorded since 2020. The flow ranged from a minimum of 361 m³/s to a maximum of 571 m³/s. These values are notably low for the time of year: the maximum discharge ranked 16th over the last 30 days, 8th among all August days since 2020, and in the lowest 4 % of all days in the record that began in 2020.

Over the past 30 days, the highest discharge was 743 m³/s on 5 July 2026, while the lowest was 321 m³/s on 2 August 2026. The current low-flow episode already appears among the five months with the lowest minimum daily flows since 2020 (Table 2). August 2026, with a minimum average flow of 442 m³/s so far, sits just above the record-low month of August 2022 (436 m³/s) and is closely followed by July 2026 (442 m³/s).

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.