Great Lakes Dam Capacity Study

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1 Great Lakes Dam Capacity Study Project Team: USACE, Detroit District Wayne State University, Detroit, Michigan Great Lakes Environmental Center, Traverse City, Michigan BUILDING STRONG

2 Study Objectives Develop an understanding of the storage capacity for sediment behind dams in the Great Lakes through monitoring, i modeling and assessment of historic i documents. How much has the construction of dams increased sediment storage in the Great Lakes? How much time do we have? BUILDING STRONG

3 Historic Anthropogenic Changes in the Great Lakes Landuse Construction of Dams Conversion/Deforestation From Dickmann & Leefers, 2003 Increased Sediment Yield/Delivery Increased Sediment Storage

4 Question: What is the anthropogenic component of sediment delivery to the US portion of the Laurentian Great Lakes? Current Condition Low Low Low???? Large Increases Large Increases Pre- Settlement St. Joe 516 Study Example Pre- 14,000 m 3 55,000 m 3 41,000 m Settlement 3 Current Condition 44,000 m 3 675,000 m 3 631,000 m 3

5 Dam Capacity Study Tasks Select 10 Reservoirs to study Through historical analysis/modeling determine: Present Sediment Erosion, Storage, and Delivery Pre-Settlement Sediment Erosion, Storage, and Delivery Field data collection Sediment Cores Reservoir Bathymetry Sediment Rating Curves Storage Capacity Analysis Long-term simulation modeling Linear Regression modeling of sediment accumulation BUILDING STRONG

6 Site Selection Riley Dam St. Joseph River (Michigan) Webber Dam Grand River (Michigan) Ballville Dam Sandusky River (Ohio) Independence Dam Maumee River (Ohio) Goshen Dam Elkhart River (Indiana) Mio Dam & Alcona Dam Au Sable River (Michigan) Brown Bridge Dam Boardman River (Michigan) St. Louis River (Minnesota) New York State (TBD) Wisconsin (TBD) BUILDING STRONG

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8 Reservoir Sedimentation: Three phases: 1. Continuous Sediment Trapping: Bedload and much of suspended load is trapped. 2. Partial Sediment Balance: Bed load is trapped, but fine sediments is removed in large flood events. Submerged floodplains form. 3. Full Sediment Balance: Long-term equilibrium of both bedload and suspended load occurs. From: Morris, Annandale, and Hotchkiss, 2008

9 Phase I Phase II

10 Independence Dam, Defiance, Ohio Phase III

11 Webber Bathymetry, Summer 2010

12 Mio Dam Core Locations BUILDING STRONG

13 Process Sediment Accumulation Rates Collect Sediment Cores in each studied reservoir Date sediment layers using radionuclide dating techniques ( 210 Pb; 137 Cs) Calculate sediment accumulation rates Develop calibrated SWAT models Run long-term simulation of studied d watersheds

14 22.3 yr BUILDING STRONG Radionuclide Dating ( 210 Pb)

15 Collect Cores cores collected in each reservoir Vibracore mounted on boat Lengths of cores 1-6 feet BUILDING STRONG

16 Cores Split into 2cm Increments for Analysis BUILDING STRONG

17 Gamma Spectrometer used to Analyze Sediment Layers BUILDING STRONG

18 Initial Sediment Accumulation Results (top 10cm) epth (cm) Linear d Equation y = a + b*x Adj. R-Square RD 13 Value Standard Error Linear depth Intercept Linear depth Slope Ln( 210 Pb xs ) dpm/g Core # # of sections Layers (cm) Slope Sedi. Rate Riley Dam cm/yr RD RD RD RD RD RD RD RD RD BUILDING STRONG

19 SWAT Modeling of Watersheds Upstream of Reservoirs Riley Dam (St. Joseph River) Existing Conditions being calibrated to flow Next step, calibrate to sediment accumulation

20 Historical Landuse Analysis Once calibrated, timevarying landuse will be input to SWAT Natural sediment loadings determined from Pre-European settlement data Percent Ag mapped for each county in pilot watersheds and input to calibrated SWAT BUILDING STRONG

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37 Multi-Variable Linear Regression Model Identify key variables than can be used to predict sediment yield, storage, and delivery for current and pre-settlement conditions Percent agricultural Clay content Basin Slope Dam density Dam network topology (parallel vs. series) Soil erodibility factor from SSURGO Parameters identified in the sensitivity analysis

38 Summary Studying 10 dams (8 currently identified) Compare bathymetry to pre-reservoir surveys Sediment accumulation rates (as a function of time) calculated using radionuclide dating SWAT models calibrated to sediment accumulation rates using varying landuse Linear regression model applied to extrapolate storage lost across the Great Lakes Region

39 Questions? Calvin Creech, PE, CFM Jim Selegean, PE, PhD BUILDING STRONG