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Marmot Dam Removal Geomorphic Monitoring & Modelling Project

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Marmot Dam Removal Geomorphic Monitoring & Modelling Project MARMOT DAM REMOVAL GEOMORPHIC MONITORING & MODELING PROJECT ANNUAL REPORT June 2008 – May 2009 Prepared for: Sandy River Basin Watershed Council PO Box 868 Sandy OR 97055 Prepared by: Charles Podolak Johns Hopkins University Department of Geography & Environmental Engineering 3400 N. Charles St, Baltimore MD 21218 Smokey Pittman Graham Matthews & Associates P.O. Box 1516, Weaverville, CA, 96093 June 2010 ACKNOWLEDGEMENTS We would like to sincerely thank all who assisted with the Marmot Dam Removal Geomorphic Monitoring & Modeling Project: Oregon Watershed Enhancement Board – funding Johns Hopkins University & The National Center for Earth-surface Dynamics (NCED) Peter Wilcock Project Advisor Daniela Martinez Graduate Assistant NCED & National Science Foundation Research Experience for Undergraduates Kim Devillier Intern Dajana Jurk Intern Cecilia Palomo Intern Tim Shin Intern Katie Trifone Intern Graham Matthews & Associates Graham Matthews GMA Principle Investigator Logan Cornelius Streamflow and Sediment Sampling Cort Pryor Streamflow and Sediment Sampling Brooke Connell Topographic Surveys Keith Barnard Topographic Surveys/Survey Data Analysis Sandy River Basin Watershed Council Russ Plaeger Director U.S. Geological Survey Jon Major Jim O’Connor Rose Wallick Mackenzie Keith U.S. Forest Service Connie Athman Gordon Grant Portland General Electric David Heinzman John Esler Tim Keller Tony Dentel Metro Parks Bill Doran Landowners Mary Elkins David Boos MARMOT DAM REMOVAL GEOMORPHIC MONITORING & MODELING PROJECT – 2009 ANNUAL REPORT ii TABLE OF CONTENTS Acknowledgements ____________________________________________________ ii Table of Contents ____________________________________________________ iii List of Tables ________________________________________________________ iv List of Figures ________________________________________________________ v Executive Summary __________________________________________________ vi 1. INTRODUCTION _________________________________________________ 1-1 1.1. Background ___________________________________________________ 1-1 1.1.1. Project Setting & History _________________________________ 1-1 1.1.2. Previous Work __________________________________________ 1-4 1.1.3. Why Sediment? _________________________________________ 1-7 1.2. Overall Decommissioning Monitoring ______________________________ 1-7 1.2.1. Collection Goals ________________________________________ 1-8 1.2.2. Partners ______________________________________________ 1-11 1.3. JHU / NCED / GMA Previous Work ______________________________ 1-12 1.3.1. Summer 2007 __________________________________________ 1-12 1.3.2. Winter 2007-2008 ______________________________________ 1-12 2. METHODS _____________________________________________________ 2-1 2.1. Overall goal____________________________________________________ 2-1 2.2. Site Selection ___________________________________________________ 2-1 2.2.1. 'At Rest' Reaches ________________________________________ 2-1 2.2.2. 'In Motion' Sites ________________________________________ 2-5 2.3. Sediment at Rest (Summer) ______________________________________ 2-6 2.3.1. Survey_________________________________________________ 2-6 2.3.2. Grain Size ____________________________________________ 2-11 2.3.3. Photos ________________________________________________ 2-14 2.4. Sediment in Motion (Winter) ____________________________________ 2-14 2.4.1. Streamflow ____________________________________________ 2-14 2.4.2. Suspended Sediment Sampling ___________________________ 2-15 2.4.3. Bedload Sampling ______________________________________ 2-15 2.4.4. Computations _________________________________________ 2-16 2.5. Annual Sediment Budget ________________________________________ 2-17 2.5.1. Boundaries ____________________________________________ 2-17 2.5.2. Storage Values _________________________________________ 2-17 2.5.3. Flux Measurements _____________________________________ 2-18 3. RESULTS ______________________________________________________ 3-1 MARMOT DAM REMOVAL GEOMORPHIC MONITORING & MODELING PROJECT – 2009 ANNUAL REPORT iii 3.1. Survey ________________________________________________________ 3-1 3.2. Grain-Size Distribution __________________________________________ 3-4 3.3. Discharge _____________________________________________________ 3-5 3.3.1. Water Year 2008 ________________________________________ 3-5 3.3.2. Water Year 2009 ________________________________________ 3-5 3.4. Suspended Load ________________________________________________ 3-6 3.5. Bedload ______________________________________________________ 3-11 3.6. Budget _______________________________________________________ 3-17 4. DISCUSSION ____________________________________________________ 4-1 4.1. Downstream Deposition__________________________________________ 4-1 4.2. Downstream Fining _____________________________________________ 4-2 4.3. Transport Measurements ________________________________________ 4-3 4.3.1. Upstream Boundary Comparisons to Estimates ______________ 4-3 4.4. Budget ________________________________________________________ 4-5 4.5. First Year Lessons ______________________________________________ 4-5 4.5.1. Geomorphic Observations ________________________________ 4-5 4.5.2. Monitoring Dam Removals _______________________________ 4-6 5. APPLICATIONS __________________________________________________ 5-1 5.1. Recommendations for 2009-2010 Monitoring ________________________ 5-1 5.2. Shared Results _________________________________________________ 5-1 5.2.1. Monitoring Team _______________________________________ 5-1 5.2.2. Local Community _______________________________________ 5-1 5.2.3. Regional Scientists & Practitioners _________________________ 5-1 5.2.4. National Scientists & Practitioners _________________________ 5-2 6. FIGURES _______________________________________________________ 6-1 7. REFERENCES ___________________________________________________ 7-1 LIST OF TABLES Table 1 - Discharge Measurements .......................................................................................................... 3-5 Table 2 - Suspended Sediment Measurements ........................................................................................ 3-7 Table 3 - Bedload Sampling Measurements .......................................................................................... 3-12 Table 4 - Bedload Sample Grain Sizes .................................................................................................. 3-12 Table 6 - Sediment Budget Inputs ........................................................................................................ 3-17 MARMOT DAM REMOVAL GEOMORPHIC MONITORING & MODELING PROJECT – 2009 ANNUAL REPORT iv LIST OF FIGURES Figure 1 - Overview of the Sandy River Basin ........................................................................................ 1-1 Figure 2 - Overview of the Bull Run Hydroelectric Project. ................................................................... 1-2 Figure 3 - Marmot Dam Site .................................................................................................................... 1-3 Figure 4 - Hydrograph for Water Years 2008 & 2009 ............................................................................. 1-4 Figure 5 - Predicted deposition from Stillwater Sciences ........................................................................ 1-6 Figure 6 - Long Profile of the Sandy River ............................................................................................. 1-9 Figure 7 - Overview of Sandy River Study Reaches ............................................................................. 1-10 Figure 8 - Overview of Dam Reach ......................................................................................................... 2-2 Figure 9 - Overview of Revenue Reach ................................................................................................... 2-3 Figure 10 - Overview of Cedar Creek Reach ........................................................................................... 2-4 Figure 11 - Overview of Oxbow Reach ................................................................................................... 2-5 Figure 12 - Surveying Setups ................................................................................................................... 2-6 Figure 14 - July 2008 Survey Points for Oxbow Reach .......................................................................... 2-7 Figure 15 - DEM generated from survey & LiDAR for Cedar Creek Reach .......................................... 2-9 Figure 16 - DEM generated from survey & LiDAR for Oxbow Reach ................................................ 2-10 Figure 17 - Facies in Revenue Reach .................................................................................................... 2-11 Figure 18 - Facies in Cedar Creek Reach .............................................................................................. 2-12 Figure 19 - Facies in Oxbow Reach ....................................................................................................... 2-12 Figure 20 - Gravelometer ....................................................................................................................... 2-13 Figure 21 - Bridge Crane Sampling Setup ............................................................................................. 2-15 Figure 22 - TR2 Bedload sampler .........................................................................................................
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