Final Coastal and Riverine High Water Mark Collection for Hurricane Katrina in Mississippi FEMA-1604-DR-MS, Task Orders 413 and 420 March 14, 2006 (Final) FOR PUBLIC RELEASE Hazard Mitigation Technical Assistance Program Contract No. EMW-2000-CO-0247 Task Orders 413 & 420 Hurricane Katrina Rapid Response Mississippi Coastal & Riverine High Water Mark Collection FEMA-1604-DR-MS Final Report March 14, 2006 Submitted to: Federal Emergency Management Agency Region IV Atlanta, GA Prepared by: URS Group, Inc. 200 Orchard Ridge Drive Suite 101 Gaithersburg, MD 20878 FOR PUBLIC RELEASE HMTAP Task Orders 413 and 420 Final Report March 14, 2006 Table of Contents Abbreviations and Acronyms ................................................................................................................... iii Glossary of Terms...................................................................................................................................... iv Executive Summary.................................................................................................................................. vii Introduction and Purpose of the Study...........................................................................................vii Methodology ...................................................................................................................................... vii Coastal and Riverine HWM Observations......................................................................................viii Hancock County ...................................................................................................................viii Harrison County .....................................................................................................................ix Jackson County......................................................................................................................ix 1. Introduction .............................................................................................................................................1 1.1 General ...........................................................................................................................................1 1.2 Purpose ..........................................................................................................................................2 1.3 Overview of Related Projects.......................................................................................................3 1.4 Overview of Hurricane Katrina.....................................................................................................4 2. Methodology............................................................................................................................................8 2.1 General ...........................................................................................................................................8 2.2 Pre-Field Deployment ...................................................................................................................8 2.3 Data Sources .................................................................................................................................9 2.4 Identification of the Study Area .................................................................................................12 2.5 Flagging Field Data Collection Procedures..............................................................................12 2.6 Survey Procedures......................................................................................................................15 2.7 USGS-Flagged HWMs .................................................................................................................15 2.8 Elevation Conversion from NAVD 88 to NGVD 29 Using Corpscon ......................................16 2.9 Quality Assurance Review .........................................................................................................17 3. Flood Types ...........................................................................................................................................19 3.1 General .........................................................................................................................................19 3.2 Coastal Flooding .........................................................................................................................19 3.2.1 Surge-Only ....................................................................................................................20 3.2.2 Wave Height ..................................................................................................................22 3.2.3 Wave Runup..................................................................................................................23 3.2.4 Impact of Dunes............................................................................................................24 3.3 Riverine Flooding........................................................................................................................25 4. Observations and Conclusions ...........................................................................................................26 4.1 High Water Mark Data Collected................................................................................................26 4.2 Coastal HWM Observations .......................................................................................................37 4.2.1 Hancock County ...........................................................................................................37 4.2.2 Harrison County ...........................................................................................................37 4.2.3 Jackson County............................................................................................................38 4.3 Riverine HWM Observations ......................................................................................................38 Hurricane Katrina Rapid Response – 1604 DR-MS Page i Coastal & Riverine High Water Mark Collection HMTAP Task Orders 413 and 420 Final Report March 14, 2006 Figures Figure 1 – Mississippi Coastal Counties ..................................................................................................1 Figure 2 – Hurricane Katrina Storm-Track................................................................................................5 Figure 3 – Hurricane Katrina Composite Imagery ...................................................................................6 Figure 4 – Forecast Katrina Storm Surge from www.Crownweather.com ..........................................10 Figure 5 – NOAA Katrina Mississippi Coast SLOSH Data ....................................................................10 Figure 6 – Interior Mud Line HWM...........................................................................................................13 Figure 7 – Exterior Mud Line HWM..........................................................................................................13 Figure 8 – Debris Line HWM.....................................................................................................................13 Figure 9 – Wrack Line HWM.....................................................................................................................13 Figure 10 – Coastal HWM Resulting from Surge-Only ..........................................................................21 Figure 11 – A Coastal Storm Surge With a Level Water Surface .........................................................21 Figure 12 – Two Cases of Storm Surges With Sloped Water Surfaces...............................................22 Figure 13 – Coastal HWM Resulting from Wave Height........................................................................23 Figure 14 – Coastal HWM Resulting from Wave Runup........................................................................23 Figure 15 – Variations in Coastal Flooding Levels Due to Washover of Coastal Dunes...................24 Figure 16 – Interaction of Profile Erosion and Coastal Flooding.........................................................25 Figure 17 – Hurricane Katrina Surveyed Locations of High Water Mark Elevations in Mississippi .............................................................................................................................27 Tables Table 1. USGS Hurricane Katrina Stream Gage Flood Stage and Discharges ...................................11 Table 2. Summary of Comparisons of USGS and URS Mississippi HWM Elevations .......................16 Table 3. Coastal Flooding Type Required For Various Uses of HWM Data ........................................20 Table 4. URS Team HWMs Surveyed by County....................................................................................26 Table 5. USGS-Located HWMs Surveyed by County ............................................................................26 Table 6. Hurricane Katrina Mississippi HWM Data Summary...............................................................28 Appendices Appendix A. Field Data Collection Forms Appendix B. HWM Location Maps and Summary Table Appendix C. Survey Sheets from Hancock County Appendix D. Survey Sheets from Harrison County Appendix E. Survey Sheets from Jackson County Appendix F. Survey Sheets for HWMs Identified by USGS: • Jackson County • Harrison County