Final Report: Introduction

Since their construction, the reservoirs behind the three dams along the lower Susquehanna River (Holtwood, Safe Harbor, and Conowingo) have historically acted as effective traps for a portion of pollution from the Susquehanna River, and the nutrients that are often attached, thereby reducing the amount of sand, silt, nitrogen and phosphorus entering the Chesapeake Bay. A recent assessment indicates that the reservoirs are trapping smaller amounts of sediment and have essentially reached their limit to trap sediment in the long term.

The Lower Susquehanna River Watershed Assessment (LSRWA) team, formed in 2011, evaluated these sediment and nutrient issues. Its final report, released March 10, 2016, includes comprehensive evaluation of the issues, findings and recommendations for management actions in the future to address the flow of pollutants downstream.

A public meeting and webinar was held December 9th in Bel Air, MD (click for agenda) Expert panelists from the LSRWA team presented a review of the issues and report results in a powerpoint,  available here (3.5MB PDF). View the full meeting webinar here (88MB mp4 file) .

Summary of the LSRWA Report

• Executive Summary of the LSRWA Final Report 0.1 MB
• Table of Contents 0.1 MB
• Lower Susquehanna River Watershed Assessment FAQ: Conowingo Dam and the Chesapeake Bay0.3 MB
• LSRWA Draft Report Press Release 0.1 MB
• LSRWA Final Report Press Release 0.1 MB
• Maryland Department of Natural Resources Press Release on LSRWA Final Report
• LSRWA Media Call - Audio File 10.4 MB

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The LSRWA Final Report (March 7, 2016)

• The Lower Susquehanna River Watershed Assessment Final Report 4.7 MB
• The Lower Susquehanna River Watershed Assessment Final Appendices 39.6 MB

Appendices

• Appendix A – Calibration of a One-Dimensional Hydraulic Model (HEC-RAS) for Simulating Sediment Transport through Three Reservoirs in the Lower Susquehanna River Basin, 2008-20112.5 MB 2.5 MB
  • A1 - Additional Information for Susquehanna River at Marietta, PA, and Conowingo, MD and Conowingo Reservoir 0.3 MB
  • A2 - Additional Information for Sand Distribution in Conowingo Reservoir 0.3 MB
  • A3 - Additional Information for Estimation of Full Sediment Storage Capacity in Conowingo Reservoir 0.3 MB
• Appendix B – Sediment Transport Characteristics of Conowingo Reservoir 1.9 MB
  • B1 - Evaluation of AdH Model Simplifications in Conowingo Reservoir Sediment Transport Modeling 0.4 MB
  • B2 - Sedflume Erosion Data and Analysis 4.0 MB
  • B3 - Change in Deposition and Bed Scour Between the 2008 - 2011 Conowingo Reservoir Bathymetry Surveys0.6 MB
  • B4 - Modeling Analysis to Support Agitation Dredging in Conowingo Reservoir 0.7 MB
• Appendix C – Application of the CBEMP to Examine the Impacts of Sediment Scour in Conowingo Reservoir on Water Quality in the Chesapeake Bay 2.5 MB
  • C1 - Data Assembly for Application of the CBEMP in the Lower Susquehanna River Watershed Assessment 0.8 MB
  • C2 - Individual Results for each Chesapeake Bay Environmental Model Package in the LSRWA are not included. Contact USACE-Baltimore District for more information.
• Appendix D – Estimated Influence of Conowingo Reservoir Infill on Chesapeake Bay Water Quality 1.1 MB
• Appendix E – Coastal and Environmental Geosciences File Report No. 14-05: Susquehanna Flats Surficial Sediment Survey, Harford and Cecil Counties, Maryland 1.1 MB
• Appendix F – USGS Conowingo Outflow Suspended Sediment Data Report 0.3 MB
• Appendix G – 2011 Exelon Conowingo Pond Bathymetry Survey Analysis 4.9 MB
• Appendix H – Literature Search Findings Report 0.5 MB
  • H1 - Evaluation of Reservoir Sediment Management Implementation 0.1 MB
  • H2 - Literature Search Overview Presentation 2.6 MB
• Appendix I – Stakeholder Involvement 0.1 MB
  • I1 - Stakeholder Outreach Plan 0.1 MB
  • I2 - Stakeholder Coordination Tracking 0.1 MB
  • I3 - Press Releases 0.5 MB
  • I4 - Study Initiation Notice 0.9 MB
  • I5 - Resource Agency Coordination 1.1 MB
  • I6 - Quarterly Meeting Summaries 1.5 MB
  • I7 - Stakeholder Review Comments 1.8 MB
  • I8 - Public Comments and Response 3.2 MB
• Appendix J – Plan Formulation 0.1 MB
  • J1 - Sediment Management Options for the Conowingo Dam Restricting Sediment in the Watershed by Implementing Best Management Practices 0.5 MB
  • J2 - Cost Documentation “Factsheets” and Summary Table of Cost 2.0 MB
  • J3 - Summary Table of Sediment Management Alternative Evaluation 0.1 MB
  • J4 - Summary Table of Major Modeling Scenarios and Results 0.4 MB
  • J5 - Summary of Model Inputs and Results for Each Significant LSRWA Model Run 0.1 MB
• K – Existing Conditions of the Watershed 7.1 MB

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