Soil water storage is systematically studied by expert from various scientific disciplines. This increased interest is mainly due to anthropogenic activities of human beings, but also due to activities of natural processes influencing the dynamics and amount of water in this water resource. The aim of this study is determination of amount of plants available soil water in the Nitra river basin for year 2013. Water storage was calculated in periods from January to March, from April to August and from October to December. Available soil water storage was determined as a difference between actual soil moisture and a hydrolimit limited water availability. Measured soil moisture was interpolated on base of point values from the net of hydrological stations in basin. Retention curves were used to calculation of limited water availability. Available soil water storage was the highest in first period (273.89 mm). In period from May to August was lower (194.32 mm) and in last period was only 152.14 mm.