This final dissertation analyses the water regime of spring Prud. Spring Prud is located in Southern Dalmatia in the Dinaric karst region. Its drainage basin is a sub-basin of the rivers Trebižat and Neretva and it is one of the main springs on the western bank of the river Neretva from which it is recharged. In this dissertation analysed parameters were monthly and annual flows for a period of 52 years. Based on the minimum, maximum and average flows it can be concluded that the spring has never dried up, i.e. during the 52-year period, a flow of 0 m3/s has never been recorded. The reason for this is continuous recharge of spring Prud with groundwater from the Trebižat drainage basin. Average annual flows were used for linear correlation analysis and represent relationships between two measurable variables. According to the Gumbel distribution, the maximum annual flows of spring Prud for the return periods of 100, 50, 25, 10, 5 and 2 years are calculated. The maximum annual flows were used in the Gumbel distribution. After all the analyses, the main conclusion is that spring Prud has a relatively significant yield, which during prolonged dry periods reduces to very low flows.