LCBP report on Sediment Loadings from Streambank Erosion released

This study, conducted by the USDA National Sedimentation Laboratory (NSL) with funding from LCBP and VT ANR, shows that a significant portion of the sediment that enters Lake Champlain from the Missisquoi River is from streambank erosion.

The study, which applied the NSL’s BSTEM (Bank-Stability and Toe-Erosion Model) tool to 30 sites on the main stem and tributaries in the U.S. portion of the Missisquoi River basin, found that 36% (36,000 tons) of the sediment that enters Missisquoi Bay each year is from streambank erosion. Hitching a ride on sediment particles is one of the primary ways that nutrients find their way to surface waters, and the study found corresponding high phosphorus loading rates. The study concluded that thirty-six percent (52 tons) of all phosphorus entering the Bay in a year originate from streambank materials. NSL’s work also confirmed the observations of other studies, noting that more than 50% of streambanks were failing in many of the reaches studied.

The researchers also looked at three scenarios for mitigating stream bank erosion with stabilization treatments. Stabilization provided by established five-year-old trees could reduce phosphorus loadings by 29%, while grading banks to a 2-to-1 slope could result in a 14% reduction. A combination of both techniques could reduce loadings by 89%.

Read the full report on Quantifying Sediment Loadings from Streambank Erosion in Selected Agricultural Watersheds Draining to Lake Champlain

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