Impacts of Channelization Along the Northern Connecticut River, Vermont and New Hampshire

摘要

Over 30 percent of the northern Connecticut River was straightened and channelized in the 19th Century for log drives. The practice of channelization continued until at least the 1960s for flood control purposes along some tributaries. Erosion and sedimentation problems persist on the Connecticut River to this day as the river continues to respond to these past management practices. Channel enlargement along the straightened reaches is largely complete except for where rock revetments were constructed in an attempt to arrest this widening. In these areas, scour can be observed around the revetments as the river channel continues to approach an equilibrium condition within the straightened reaches. Sharp bends in the channel created where straightened reaches reconnect with more naturally meandering portions of the channel are currently the sites of active erosion. Erosion pressures will remain until a more natural smoother bend develops so attempts to armor the bends in their current configuration will not likely meet with longer term success. Recognition of where these erosion pressures exist will help identify high priority areas for riparian buffer restoration.