This Dataverse contains the data used in the manuscript entitled "Scale-free structure of surface-water connectivity within a lowland river floodplain" by Cesar R Castillo, İnci Güneralp, Billy Hales, and Burak Güneralp. The corresponding author is Cesar R Castillo and can be contacted at castillocesar@tamu.edu. Data included in this Dataverse is the digital terrain model (DTM) used in the hydrodynamic modeling, the ensemble of 23 hydrodynamic simulations, the soil- and vegetation-based landscape patches, the ensemble of 23 connected soil- and vegetation-based landscape patches, the ensemble of 23 surface-water connectivity networks, tables of the data used in the empirical scale-free analysis, tables of the topological and algebraic metric values used in our analysis, and the data values in the hydrodynamic model calibrations with the FEMA-FIS data.