ABSTRACT
Water-and nutrient-exchange between surface water and groundwater affects the water quality of both water bodies and, thus, is important for their management. To find out more about the exchange processes a site surrounded by the present river bed and an old branch of the lowland River Spree was equipped with a transect of twelve observation wells. Infiltration and exfiltration of the surface water into the groundwater alternates depending on precipitation and water level fluctuations of the River Spree. Biogeochemical data revealed much more spatial variability than previously thought which might partly be caused by peat mineralisation of relict layers in the soil and by upwelling deep groundwater. Temporal variability of the biogeochemical data is usually low, there are few wells where alternation of in-and exfiltration causes considerable concentration changes.
