This study presents results of simultaneous measurements’ series of flow intensity made in more than 60 rivers sections of Oława, Ślęża, Czarna Woda, Lower Bystrzyca, Strzegomka, Średzka Woda, Cicha Woda, Niecka and Wierzbiak rivers. Surfaces of these areas include clay soils mainly with loess origin. These soils shows low horizontal flow abilities of underground water together with high soaking conditions and natural capillary lift. Area of research has one of the lowest underground water outflow in Poland because of all conditions mentioned above and come to 7-9% of year precipitation (Sawicki, 1978). The deepest low-flow of underground outflow occurs on summer when the evaporation is highest. Atmospheric and hydrological drought occurred on these areas on late autumn and early winter of 2011. I n this period of time rivers were supplied by underground water outflows only so recognizing those outflows was main reason of making research. Area of basin and total length of whole active rivers net. Measured flows was converted to 1 square km and 1 km of river bed length. Results has been compared with long-term results of researches made by IMGW and PiG on their measurement stations. Result was also compared with Ph.d thesis written by author (Sawicki, 1978).