The recording of low flows, including base flow, has particular importance in the case of intensive draw-offs of water from a water-course. It provides a basis for the proper water management of a water intake and ensures that the flows creating the right conditions for the survival of water organisms and vegetation are maintained. The paper presents the results of the geodetic and hydrometric surveys conducted on the Uszwica river during three years of the building of a water gauge. The latter was built with the aim of recording the base flow, in accordance with the permit required by the Water Law Act and issued for the damming-up and draw-off of water by the Okocim Brewery. At the water levels lower than the base flow, the brewery has no right to take water from the Uszwica river. The measurements and the developed rating curves showed that the geometrical changes in the river’s cross-section caused by the passing flood waves have a significant influence on establishing the water level at the base flow. The change in water depths and the ordinates of average low and base flows in the gauging section were determined.

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