Damming up in the river channel caused by the dam on the underground waters then, when the hydraulic relationship of superficial waters and underground waters exists. The study of the forecast of the influence of damming up the river waters on adjoining areas consists in the qualification of the position of the underground water level. The tests of the appraisal of the position of the ground water level on the terrain of locality Zembrzyce in the case of damming up the water in the reservoir to the ordinate 312 m a.s.l were executed. Distribution of the filtration area is extremely difficult in spite quite good distinguishing the hydro-geological conditions of the analysed area. The locality Zembrzyce is in fork of two water - courses: river Skawa and her tributary the stream Paleczka. Location of Zembrzyce in these fork of two rivers creates complicated hydro-geological conditions resulting from the interaction of superficial water - courses on the adjoining area. On the studied area the zone of the influence of the change of the water level in river Skawa and stream Paleczka on the level of the ground waters was marked. Applying the hydrological method the change of the position of the ...