On 1 November 2025 Warsaw’s hydrometeorological authorities lowered the Vistula zero‑point at Bulwary and Gusinie by 100 cm, raising gauge readings without changing river flow.
Zero‑Point Adjustment
Since 1 November 2025, the zero reference at two Warsaw Vistula water gauges—Gusinie and Warszawa‑Bulwary—was lowered by 100 cm. The modification results in higher gauge readings but does not signify an increase in water volume.
Authority Actions and Rationale
Two notices (72/2025 dated 16 October and 79/2025 dated 3 November) corrected gauge readings, establishing a new reference point. The Warsaw Regional Water Management Board implemented the change at the request of the Polish Institute of Meteorology and Water Management to standardise the reference system and prevent misleading negative readings when river levels are very low. Polish Waters warns that initial readings after the change may be confusing, urging caution when planning activities on the Vistula and its banks.
Effect on Readings and Safety
Polish Waters states the decision stems from persistently low flows and bed erosion, which risked sub‑zero readings and hindered data comparison. The change applies only to the reference point—it does not affect the actual hydrological status, merely the presentation of measurements.
