Climate change is having a major impact on the amount of water in the reservoir as well as the appearance of large flood waves. One of the key elements for monitoring climate change is temperature changes and the amount of evapotranspiration. Even slight changes in temperature affect the distribution of precipitation throughout the year and the amount of precipitation. The catchment area network of the multi-purpose reservoir Modrac is made up of three larger streams: Spreča River, Oskova River, and Turija River. In the design and construction of the dam and the multi-purpose reservoir Modrac, it was planned that it serves as a multiuse water management system. This paper provides information on temperature change trend (minimum and maximum temperatures), amount of precipitation, and evapotranspiration and analyzed maximum flood waves for the reservoir Modrac for the period 2001-2020. Available data will be extensively tested using a variety of inferential statistical methods between predictor and response variables in order to prove/disprove the formed hypothesis based on the obtain statistical test results.

Keywords : Hydrological, Meteorological, Change and Variability, Reservoir Modrac, Temperature, Precipitation, Evapotranspiration, Flood Waves