The paper presents the characteristics of water relations and assessment of changeability of soil retention resources in the Southern Park in Wrocław. The assessment was done on the basis of measurements of soil water content in 2012 and 2013 also the results of field investigations from earlier years were taken into account. The measurements of soil water content were done using TDR method in the upper soil layers 0–25 cm and 25–50 cm in several dozen points (about 60) on the area of Park. It allowed to generate the maps of spatial distribution of soil water content. It was found that on the area of park there was observable diversity of retention resources accumulated in soils. Explicitly higher values of moisture were observed in the vicinity of park pond. The researches and analyses showed that excessive water content in analyzed soils in the area of Park occurred usually in spring and after torrential rains. The value and distribution of precipitation had the highest influence on soil retention resources forming.