Economic gains of use have led to a global explosion of groundwater development in the last several decades. Consequently, groundwater reserves have been depleted extensively. Continuing use of groundwater, which is initially supplied from the storage, causes increasing derivation of additional water from groundwater dependent ecosystems such as, streams, lakes and wetlands. A systematic groundwater age dating in the vicinity of a surface water body may help to quantify the spatio-temporal dynamics of interaction between these resources. Though, numerical flow and transport models may be used to infer the age distribution of groundwater feeding a surface water body, their efficient use requires extensive data that properly characterize the flow domain. In cases, such data is not available or requires to be supplemented by an independent approach, spatio-temporal age dating of groundwater by various tracers can be helpful in understanding the dynamics of flow in the aquifer. This paper provides brief information on how the groundwater age data can be used in surface water ecological problems. Examples from several field sites in Turkey are also presented.