Abstarct: Abstract In small water reservoirs, the energy exchange between the air-water interface is crucial in determining the evaporation rate, directly impacting water resource management strategies. Sensible heat flux is a key component among these exchanges, and its study is essential to understanding the evaporation processes. Despite extensive research, the appropriate evaluation of this quantity under the influence of water surface flows and wind in small reservoirs remains unexplored. This study aims to fill this research gap by experimental and analytical investigation of the impact of surface flows on sensible heat flux between the air-water interface in small open reservoirs affected by varying wind speeds. The evaluation of heat fluxes in small reservoirs is performed to identify factors influencing surface evaporation and select appropriate strategies for controlling and reducing it, alongside the analysis of sensible heat flux, evaporation rates, and the Bowen ratio (the ratio of sensible heat flux to latent heat flux) are also examined. To achieve these objectives, a 500-liter polyethylene reservoir is used as the water storage basin, a heat flux sensor is employed to measure sensible heat flux, 500W Osram lamps simulate solar radiation, a fixed pump is used to generate water surface flow, two fans created wind, and other equipment such as an evaporimeter, thermometers, etc., are utilized. The results show that water surface flow increases sensible heat flux, which is more pronounced when wind is present. When the direction of water surface flow is opposite to the wind direction, the increase is more significant than when both are aligned. The interaction between the changes in sensible heat flux and the thermal mixing of water laxyers causes evaporation to decrease with a surface flow rate of 7.5 l 〖min〗^(-1) when the wind speed is 1.4 m s^(-1). Beyond this point, evaporation begins to increase. As wind speed increases, the 7.5 l 〖min〗^(-1) flow rate starts to retreat until it reaches 1 l 〖min〗^(-1) at a wind speed of 2.0 m s^(-1). When the direction of water surface flow is opposite to the wind direction, the optimal flow rate across all test conditions is at its minimum, i.e., 1 l 〖min〗^(-1). To generalize the findings of this research to small reservoirs with real-world environmental conditions, dimensional analysis and identification of dimensionless numbers baxsed on the influencing variables are carried out. Three regression equations are derived between the experimental Bowen ratio and dimensionless numbers under all test conditions. The performance of these equations is examined in the research reservoir at Isfahan University of Technology under real conditions, showing acceptable agreement (R² > 73%).