The Connecticut River floodplain at the confluence of the Upper Ammonoosuc River shown here includes topographic features such as coves, oxbows, backswamps, swales and point bars with frequent and long duration flooding providing ample habitat for flood-dependent species. Note that the natural levees along the upstream banks of some of the meander bends are among the highest elevation features in the floodplain falling in the range of the 1.1 to 2 year recurrence interval flood stage, consistent with the conventional definition of “bankfull” flow. The watershed area upstream of the Upper Ammonoosuc River confluence is 3000 km2 and is almost completely forested, had little development, and there are no upstream flood control dams. There is no evidence for a shift in hydrologic regime over the period of record for the two USGS stream gages in the area which go back to 1927 and 1930. See Maidstone Bends and Upper Ammonoosuc Confluence sites in Table S1 for details of measurement methods used in this reach.
