Stream Geomorphic Assessments

Williams River –Assessment and Protection of the State’s Water Quality

Final Product: Williams River Corridor Plan

The Windham County Natural Resources Conservation District (WCNRCD) implemented an Ecosystem Restoration Program Grant Award in 2016 from the State of Vermont’s Department of Environmental Conservation for the dual purpose of protecting the State’s water quality and supporting WCNRCD’s goal to conduct Stream Geomorphic Assessments (SGAs) in Basin 11 and all of its subwatersheds. Basin 11 is located in the southeastern corner of Vermont and drains the eastern slopes of the Green Mountains, encompassing the three watersheds of the West, Williams and Saxtons Rivers. Like much of Southern Vermont, the Williams River was impacted severely by Tropical Storm Irene, yet is the only un-assessed river remaining in the three subwatersheds of Basin 11. According to Chris Campany of the Windham Regional Commission (WRC), “Irene underscored the importance of understanding the science and physics underlying the behaviors of our rivers and streams. This knowledge is critical to town and regional planning, and information about stream and river behavior needs to be more broadly understood by the general public.”

 

The Phase 2 Stream Geomorphic Assessment and River Corridor Plan on the Williams River watershed continued the work initiated in 2013 by the WCNRCD.  The WCNRCD conducted a Phase 1 SGA on 106 miles on the Williams River that also included (14) tributary watersheds, and two sub-tributary watersheds.  The Phase 1 Report was completed in April 2014.   The completed Phase 2 and River Corridor Plan for Williams River watersheds was the product of this most recent grant. The plan includes a detailed assessment of selected reaches for geomorphic condition, habitat condition, a bridge and culvert inventory, an analysis of stressors in the river corridor, sediment regime maps, and an estimate of the river’s sensitivity to changes in flow.

The completed River Corridor Plan identifies, develops and prioritizes a list of recommended restoration projects for implementation to stabilize and restore the river corridor based on the SGA findings. The overall Management Plan for Basin 11 was completed and adopted in June 2008, and recommended the completion of SGAs as a Priority Project for water quality.  Marie Levesque Caduto, chief author of the plan, stated “ The Williams River assessment work will guide the Agency of Natural Resources as we develop and fund the on-the-ground projects that will improve not only the water quality in the river but the aquatic habitat and the fishery as well.”

 

This grant provided the funds to conduct a Phase 2 SGA on approximately 44 reaches on the Williams River, which includes the Middle Branch, South Branch and the Andover Branch. Windham Reginoal Commission’s Chris Campany notes that “Irene was an extreme event in terms of its overall scale, but damaging floods occur on our streams and rivers on a regular basis.  Knowing what areas are likely to one day flood and/or erode can save heartbreak, property and lives, and point us to what riparian zones should be conserved and not developed.” The assessment work started in June 2014 and was completed in September of 2016. Results were presented at public meetings following completion.

 

WCNRCD has previously partnered with the Vermont Agency of Natural Resources and WRC to complete SGA’s and Corridor Planning projects on the Saxtons, West, Rock Rivers and the Whetstone, Crosby, and Ball Mountain Brooks.