Groundwater heat pump (GWHP) system is an efficient technology that can provide both heating and cooling to buildings, leading to considerable energy savings. During operation, injection can cause a change in the abstraction temperature, known as thermal feedback, a well-studied phenomenon over the years mainly based on numerical studies. However, there are only a limited number of experimental studies exploring the impacts of groundwater flow rates and different operational configurations for cooling and heating systems on thermal plume development for a well doublet. To address this gap, a laboratory-scale experimental investigation was conducted for cooling and heating operation of soil, considering two different operation types: Cooling and Heating (CH), and Aquifer Thermal Energy Storage (ATES). The setup was designed to conduct the experiments under groundwater flow to investigate its impact on thermal feedback. The results suggest that the ATES operation significantly enhances efficiency by utilising stored groundwater from cooling period for the heating period. The ATES operation led to a 29% increase in efficiency during the heating period when compared to CH operation. The influence of the presence of groundwater flow was found to be less than 10%, although it may have a more significant impact in long-term operation as it disperses the thermal plume, affecting the abstraction temperature further.