This paper summarizes a case study of an innovative ground-source heat pump (GSHP) system that uses flooded mines as a heat source and heat sink. This GSHP system provides space conditioning to an existing 56@000 ft2 (5203m2) research facility@ in conjunction with existing space heating and space cooling systems. Heat transfer performance and overall efficiency of the GSHP system were analyzed using the available measured data from January through July 2014. The performance analysis identified some issues with using mine water for cooling and the integration of the GSHP system with the existing steam heating system. Recommendations were made to improve the control and operation of the GSHP system. These recommendations@ in conjunction with the available measured data@ were used to predict the annual energy use of the system. Finally@ the energy and cost savings and CO2 emission reduction potential of the GSHP system were estimated by comparing them with a baseline scenario. This case study provides insights into the performance of and potential issues with the mine-water-source heat pump system@ which is relatively underexplored compared to other GSHP system designs and configurations.