A novel method to evaluate the effect of a stream restoration on the spatial pattern of hydraulic connection of stream and groundwater

•Effects of river stage fluctuations were traced through a riverine aquifer.•Clear spatial patterns of enhanced permeability were identified.•An oxbow was shown to be hydraulically decoupled from the aquifer.•Restoration of the oxbow did not improve connectivity to the aquifer significantly.•The floodplain sediment structure played a larger role than a former clogging layer.