Floodplain encroachment has many ramifications. The present study investigates the possibilities of scour and excessive backwater resulting from the construction of the Columbia Generating Station on the Wisconsin River floodplain near Portage, Wisconsin. Neither scour nor excessive backwater appear to be problems in the study area, not even for the 100-year (regional) flood. A possible change in climate since 1950 does not alter the expected results of floodplain encroachment. However, the effects of the proposed climatic change, manifested by a shift from predominantly zonal to predominantly meridional circulation patterns, cannot be fully determined. Limited data, few choices of analytical methods, and the possible masking of any effects by reservoir development all contribute to the inconclusiveness of the analysis of climate change and its possible effects on the study problems. (Author).