, Senate Resolution 172 Response January 2019 Prepared for: Louisiana Department of Transportation & Development Prepared by: Arcadis Senate Resolution 172 Response SENATE RESOLUTION 172 RESPONSE January 2019 Contents Acronyms and Abbreviations ...................................................................................................................... iv Introduction ................................................................................................................................................... 1 Part 1. Impacts of Channelization, Dredging, and Clearing and Snagging Activities Upon River Basins and Water Transmission ...................................................................................................................... 2 1.1 Regulatory Considerations .................................................................................................................. 2 1.2 Stakeholder Engagement..................................................................................................................... 3 1.3 Impacts of Channel Maintenance and Construction Projects ............................................................. 4 1.3.1 Channelization ............................................................................................................................. 5 1.3.2 Dredging ....................................................................................................................................... 7 1.3.3 Clearing and Snagging ................................................................................................................. 9 1.4 Amite River Basin Dredging Analysis .............................................................................................. 11 1.4.1 Dredging Scenarios .................................................................................................................... 11 1.4.2 Analysis Results and Conclusions ............................................................................................. 12 1.5 Conclusions .................................................................................................................................. 13 Part 2. Statewide, Comprehensive Watershed-Based Floodplain Management ......................................... 14 2.1 Progress Since Release of the Phase I Report ................................................................................... 14 2.2 Related Commissions, Committees, Initiatives, and Programs ........................................................ 17 2.2.1 Louisiana Water Resources Commission ................................................................................... 17 2.2.2 Louisiana State Law Institute Water Code Committee .............................................................. 17 2.2.3 Louisiana Resilient Recovery Initiative ..................................................................................... 17 2.2.4 Existing State Agency Programs and Responsibilities .............................................................. 17 2.3 How are roles and responsibilities assigned to establish, implement and enforce watershed-based floodplain management plans across the state? ................................................................................. 20 2.3.1 Identification of Watershed-Based Roles ................................................................................... 20 2.3.2 Watershed-Based Roles by Functional Area .............................................................................. 21 2.3.3 Next Steps and Recommendations ............................................................................................. 23 2.4 What geographic scale and boundaries should be used for watershed-based planning in Louisiana?.. .................................................................................................................................. 24 2.4.1 Scientific and Modeling Considerations .................................................................................... 25 Page i Senate Resolution 172 Response 2.4.2 Watershed-Based Planning Objectives ...................................................................................... 25 2.4.3 Existing Organizational Boundaries .......................................................................................... 26 2.4.4 Previous Studies and Investigations ........................................................................................... 26 2.4.5 Next Steps and Recommendations Regarding Geographic Scale and Boundaries for Watershed- Based Planning .......................................................................................................................... 27 Part 3. Recommendations ........................................................................................................................... 29 Part 4. Progress Planned for 2019 ............................................................................................................... 36 Tables (in text) Table 1. Current Statutes and Regulations Pertaining to Channelization, Dredging, and Clearing and Snagging Table 2. SR 172 Response Channelization, Dredging, and Clearing and Snagging Research Stakeholders Table 3. Impacts of Dredging Table 4. Summary of Dredging Alternatives 1, 2, and 3 Table 5. Maximum Decrease and Increase in Water Surface Elevation Based on Alternatives 1, 2, and 3 Table 6. Summary of Progress Since Release of Phase I Report Table 7. State Agency Programs that Must Be Coordinated with the LWI to Maximize Effective Flood Risk Management Table 8. Potential Watershed-based Coalition Roles and Example Case Studies Table 9. Potential Role of a Watershed-based Coalition by Functional Area Table 10. Evaluation of Geographic Flood Control Alternatives Adapted from the SCR 39 Report Table 11. Recommended Actions for Establishing, Implementing, and Enforcing Floodplain Management Plans for Each Watershed in Louisiana Table 12. Planned Activities for 2019 Page ii Senate Resolution 172 Response Figures (in text) Figure 1. Watershed Planning Configurations Should be based on Scientific and Modeling Considerations, Watershed-Based Planning Objectives, and Consideration of Existing Organizational Boundaries Figure 2. Planning and Development District Boundaries When Compared with HUC-4, 6, and 8 Watershed Boundaries Figure 3. Parish Boundaries Comparison Figure 4. FHBA3 Compared to Existing Flood Infrastructure Figure 5. FHBA3 Compared to Existing Population Centers Appendices Appendix A Annotated Bibliography Appendix B Part 2 Attachments Attachment B.1 Stakeholder Input Teleconference Call Summaries Attachment B.2 Investigation into the Potential Hydraulic Impacts of Dredging the Lower Amite River Appendix C Part 3 Attachments Attachment C.1 Technical Advisory Group Council Briefing Attachment C.2 Initial plan for the build out of the “everything flood related website and data portal" Attachment C.3 Description of Data Reports Under Development Attachment C.4 Implementation roadmap progress by strategic area of focus Page iii Senate Resolution 172 Response ACRONYMS AND ABBREVIATIONS CDBG-DR Community Development Block Grant – Disaster Recovery Council Council on Watershed Management CPRA Coastal Protection and Restoration Authority CRS Community Rating System DNR Department of Natural Resources DOTD Louisiana Department of Transportation and Development FEMA Federal Emergency Management Agency FHBA Flooding Hazard Based Alternative FPC Facilities Planning and Control GOHSEP Governor's Office of Homeland Security & Emergency Management HU hydrologic unit HUC hydrologic unit code HUD U.S. Department of Housing and Urban Development IDNR Illinois Department of Natural Resources LCMP Local Coastal Management Programs LDEQ Louisiana Department of Environmental Quality LDH Louisiana Department of Health and Hospitals LDWF Louisiana Department of Wildlife and Fisheries LED Louisiana Economic Development LWI Louisiana Watershed Initiative LWRC Louisiana Water Resources Commission NFIP National Flood Insurance Program OCD Office of Community Development OTS Office of Technology Services Phase I Report Phase I Investigation Report: Louisiana Statewide Comprehensive Watershed Based Floodplain Management Program Development Response Report SR 172 Response Report RFP request for proposals RFQ request for qualifications SCR Senate Concurrent Resolution SOP standard operating procedure Page iv Senate Resolution 172 Response SR Senate Resolution TAG Technical Advisory Group USACE United States Army Corps of Engineers USFWS United States Fish and Wildlife Service USGS United States Geological Survey WBD Watershed Boundary Dataset WQC water quality certification Page v Senate Resolution 172 Response INTRODUCTION Louisiana Senate Resolution (SR) 172 of the 2017 Regular Legislative Session, co-authored by Senators Mack A. “Bodi” White and Sharon W. Hewitt, directed the Louisiana Department of Transportation and Development (DOTD), in consultation with other state agencies, to “study construction or maintenance impacts, including channelization, dredging, and clearing and snagging activities, upon river basins and water transmission, and provide recommendations to establish, implement, and enforce floodplain management plans for each watershed in Louisiana.” DOTD, in consultation with the Federal Emergency Management Agency (FEMA), Louisiana Department of Environmental Quality (LDEQ), Louisiana Department of Wildlife and Fisheries (LDWF), Louisiana