Dynamics of underground water in floodplain forest in the Morava river alluvium in South Moravia is primarily dependent on hydrological conditions as main recipient of Morava, Kyjovka & Spářavka. Hydrological measures carried out in 2nd half of 20th century have caused a negative impact on this floodplain groundwater. Increasing climatic extremes (low precipitation, high evapotranspiration) caused decreasing moisture content in surface soil layers. The aim of the study was to evaluate the underground water dynamics of 2018 in model area of Mikulčice forest using GIS and compare the result with previous studies to get the long term trend of changing underground water and soil moisture regime. Results show that the underground water level dropped to more than 2m from the surface in the sand and gravel layer almost throughout the year which interrupted capillarity of the soil profile. The underground water dynamics in the vegetation period was only on average 0.75m which is almost flat. Soil moisture dropped to lower than hydrolimits of availability of water for plants in the vegetation period. Measured tree increment of main trees was very low and some trees are permanently in stress. Finishing of revitalization in this area with the aim of improving the negative situation is Important for future years.