Summary:

Buildings the cascade of water barrages of the section of the Upper Vistula contributed to the change of water relations in the valley of the river. Possessed observational material, relating to the recognitions of hydrogeological conditions on the area of the influence of the Dwory Water Barrage, allowed to conduct the analysis of the position of land waters. Using results of measurements executed in wells in the period before damming up water in the river Vistula relationships of the mirror of the ground water and water in the river Vistula were worked out. They made possible the qualification of the water level on the analysed area in the conditions swell the water in the river Vistula to the ordinate 225,50 m a.s.l., the elaboration of maps hydro-isohips and the qualification of the influence range of damming up through delimitation of the zones of the direct threat of soppy terrains situated in the environs of the locality Gromiec and Szyjki. The pronouncement of soppy areas was affirmed, about depth of covering the mirror of ground water to 0,8 m, partly soppy areas, about depth of covering the mirror of ground water from 0,8 from 1,6 m and neutral areas.