Subsurface travel time from the area of recharge to the point of abstraction during MAR is a critical parameter to ensure sufficient attenuation for hygienic parameters and other undesired substances. A new simulation tool has been developed by the SMART-Control project partners KWB and TUD for determination of groundwater hydraulic residence time (HRT) using seasonal temperature fluctuations observed in recharge water and MAR recovery wells. This tool represents a proxy for quick, costs-effective and reliable control of travel time during aquifer passage. Time series of seasonal temperature measurements observed in surface water and abstraction wells can be fitted to sinusoidal functions. Peak values represented as local maxima and local minima and turning points from the fitted sinusoidal curves are used for the approximation of travel times between surface water and abstraction well. The calculated values are adjusted by a thermal retardation factor. The developed tool is userfriendly and offers the possibility to use existing hystorical temperature measurements as well as online sensor data. Data acquisition is resolved through the internal connectivity with other web-tools developed within the SMART-Control project, providing thus an integrated simulation environment.