This paper presents a numeric model of ground water flow in the Wapno salt dome area. The model was perform in order to verify a conceptual system of water circulation and to determine the influence of geological factors on the formation of hydrogeological conditions in the salt dome region. Besides, the prognosis of saline water migration from the caprock to the exploited aquifer was made. The model was performed by means of the Modflow program, which does not include the water with differentiated mineralization. This caused some serious problems during model construction and its calibration affecting the reliability of the obtained results of water balance.