Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers River Bank Erosion Siskiwit River, Cornucopia, WI

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Sediment Budgets Upland Sources Streambank Sources From Reid & Dunne, Rapid Assessment of Sediment Budgets, 1996

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers How Do we Measure Bank Erosion?

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Great Lakes Bank Erosion Project The Big Questions… What are bank erosion rates in Great Lakes rivers? How significant is the bank component in Great Lakes sediment budgets? What are bank erosion rates in Great Lakes rivers? How significant is the bank component in Great Lakes sediment budgets?

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers The Big Questions…continued Are there simple methods that can be used to estimate bank erosion rates in the field? Answer…No

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Lateral Movement of bank. Measured in feet/year Resisting Force Intrinsic property of bank. Function of: Soil Vegetation Bank Angle Etc. Driving Force Property of the hydraulics. Function of: Near Bank Shear Stress Bank Erosion

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Bank Erodability How do we determine how susceptible a bank is to erosion?

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Predicting Bank Erosion Bank Erosion Hazard Index (BEHI)

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Bank Height Ratio Root Depth Ratio Weighted Root Density Bank Angle Surface Protection Bank Material Stratification Bank Height Ratio Root Depth Ratio Weighted Root Density Bank Angle Surface Protection Bank Material Stratification BEHI Variables

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Low Erosion Potential Black River, Michigan (UP)

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Moderate Erosion Potential Coldwater Creek, Union City, Michigan

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Very High / Extreme Erosion Potential Ontonagon River, Michigan (UP)

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Bank Erosion Bank Erosion Hazard Index (BEHI) Near Bank Stress (NBS) Index

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Near Bank Stress 1. Channel patterns, transverse bar or split channel/central bar 2. Ratio of radius of curvature to bankfull width 3. Ratio of pool slope to average water surface slope 4. Ratio of pool slope to riffle slope 5. Ratio of near-bank maximum depth to bankfull mean depth 6. Ratio of near-bank shear stress to bankfull shear stress 7. Velocity profiles / Isovels / Velocity gradient 1. Channel patterns, transverse bar or split channel/central bar 2. Ratio of radius of curvature to bankfull width 3. Ratio of pool slope to average water surface slope 4. Ratio of pool slope to riffle slope 5. Ratio of near-bank maximum depth to bankfull mean depth 6. Ratio of near-bank shear stress to bankfull shear stress 7. Velocity profiles / Isovels / Velocity gradient

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers NBS#1 - Channel Patterns Transverse and/or central bars – short and/or discontinous – NBS = High or Very High Extensive deposition – NBS = Extreme Chute cutoffs, down-valley meander migration, converging flow – NBS = Extreme Transverse and/or central bars – short and/or discontinous – NBS = High or Very High Extensive deposition – NBS = Extreme Chute cutoffs, down-valley meander migration, converging flow – NBS = Extreme

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers NBS#2 – Ratio of Radius of Curvature (R c ) to Bankfull Width (W bkf ) R c /W bkf Rating > 3.00Very Low 2.21 – 3.00Low 2.01 – 2.20Moderate 1.81 – 2.00High 1.50 – 1.80Very High < 1.50Extreme Generally R c Performed Using Aerial Photography

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers NBS#3 & #4 – Ratio of Pool Slope to Average Slope (S p /S) or Riffle Slope (S p /S rif ) S p /S rif Rating < 0.40Very Low 0.41 – 0.60Low 0.61 – 0.80Moderate 0-81 – 1.00High 1.01 – 1.20Very High > 1.20Extreme

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers d nb /d bkf Rating < 1.00Very Low 1.00 – 1.50Low 1.51 – 1.80Moderate 1.81 – 2.50High 2.51 – 3.00Very High > 3.00Extreme NBS#5 – Pool Depth to Average Depth

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Measuring Bank Erosion

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Bank Erosion Bank Pins & Bank Profiles Bank Erosion Hazard Index (BEHI) Near Bank Stress (NBS) Index

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Bank Profile Measurement Equipment Toe Pin (rebar) Toe Pin Cap Hammer Survey Rod (2) or Survey Rod & Pocket Rod Line Level Rod Level Field Forms Equipment Toe Pin (rebar) Toe Pin Cap Hammer Survey Rod (2) or Survey Rod & Pocket Rod Line Level Rod Level Field Forms

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Measuring Bank Profile Source: Arkansas Department of Environmental Quality

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Comparison of Bank Profiles

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Bring it all Together Regional Curves

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Great Lakes Curves - Preliminary

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Is there a better correlation for predicting bank erosion? Remotely-sensed data Radius of curvature Meander wavelength Beltwidth:valley width Valley slope Soils maps for resistance and infiltration Remotely-sensed data Radius of curvature Meander wavelength Beltwidth:valley width Valley slope Soils maps for resistance and infiltration

Detroit District, Hydraulics & Hydrology Office US Army Corps of Engineers Questions? Contact: Dr. Jim Selegean, P.E., P.H. U.S. Army Corps of Engineers, Detroit District Great Lakes Hydraulics and Hydrology Office 477 Michigan Ave Detroit, MI