This paper presents results of the analysis of water regime of the source area of Plitvice Lakes. The Plitvice Lakes National Park is located in the central part of the Dinaric karst region in the Republic of Croatia. The natural phenomenon of this area presents 16 cascading lakes separated by tufa barriers that form attractive waterfalls. The paper presents analysis of the water flow trends registered at the most important hydrologic stations in the area of Plitvice Lakes, and the analysis of water balance and recession periods of the source area. As for the meteorological parameters, air temperature and rainfall were analysed. There is a lack of data from some hydrologic stations due to shorter or longer breaks in operation, especially from 1991 to 1995, when all measurements were interrupted as per war. Therefore, different periods data is analysed depending on the data availability of a certain station. Hydrologic analysis were carried out on annual, monthly and daily basis. High correlation between the main annual water flow rates of most analysed hydrologic stations indicates a relatively strong correlation between their water regime. The largest water resources of the Plitvice Lakes are the karst springs Bijela and Crna River with average annual discharge of 0,482 m3/s and 1,469 m3/s. Watercourses of Bijela and Crna River form Matica River which flows into the Lake Prošće, with an average annual flow rate of 2,364 m3/s, which consists of the Bijela River of 20-23%, the Crna River 66-67%, and the remaining 11-13% originates from smaller surface tributaries. Recession periods of Bijela and Crna River in several driest years were analysed too, in order to establish the most relevant recession curves. Using the machine learning methodology, a hydrological model for predicting the dynamics of oscillations in the levels of Lake Prošće was developed, based on hydrological and meteorological parameters as input variables.