The aim of this research was to determine the influence of meteorological and hydrogeological factors on the changes to water levels in the rainwater storage and infiltration reservoir. The examined reservoir is located in the urban and industrial area of Krakow, on ground owned by the Polish State Railways (PKP) Kraków-Bieżanów branch. The analysis of a range of climatic (precipitation and evaporation) and hydrological factors (water stage in reservoir and ground water level) and their inter-relationships can help to determine their influence on the water depth regime in the storage and infiltration reservoir. On the basis of the analysis, it can be stated that the increase of the water table level in the reservoir is connected with the increase of the ground water level and it is observed in the spring and summer periods, when there is a supply of water from thawing snow and ice and storm water in summer. The groundwater is fed by filtrating meltwater and increase of the groundwater table level can be observed at the end of July and this is caused by excessive rainfall events. Throughout the whole period of testing, the reservoir was fed by infiltering groundwater from the area of the basin located higher up the reservoir. Finally the water depth averages in the reservoir are closely correlated with average levels of groundwater table, the sum of precipitation from the week prior to the date of the examination of water depth in the reservoir, the sum of potential evaporation in the given week.