Data center cooling systems are major energy consumers, operating continuously throughout the year. And because of this, the provision of low-cost cooling is challenging. In recent years, researchers have focused on integrating potential renewable energy sources to reduce energy usage in these systems. This study examines the potential for energy saving potential of a newly developed hybrid dam water cooling system for data centers, which functions in free and forced cooling modes. Firstly, the study conducted an experimental comparison between the performance of the hybrid system and that of a conventional air source cooling system based on variations in heat source temperatures. Both systems were then modelled in EnergyPlus using data from the Soyang Dam in Chuncheon, South Korea, to assess their seasonal and annual energy consumption. Compared to the conventional system, the hybrid dam water cooling system had approximately 76.2 %, 66 %, and 21.6 % energy savings in the winter, spring, and summer seasons, respectively, and 48 % annual energy savings. These savings are attributed to the efficient free cooling mode of the system, the stable temperature of the heat source, and the reduced compressor cycling frequency in forced mode. Furthermore, compared to the hybrid system in forced cooling, the energy consumption of the hybrid system in free cooling mode was insignificantly affected by the changes in dam water temperature. This confirms the energy saving potential of the hybrid system in free cooling mode.