Prepared for the National Institute of Building Sciences
July, 2009

The Association of State Floodplain Managers (ASFPM) produced this report with funding from the National Institute of Building Sciences (NIBS). This project was performed as:
Project No. 813; Contract No. 2, Modification 1, between ASFPM and NIBS
This report was prepared by Earth IT LLC, Madison, Wisconsin. Insightful review, detailed comments and discussion were provided by Neil C. Blais – Blais and Associates Inc.; Nikolay Todorov – ABSG Consulting Inc.; Kevin Mickey, The Polis Center, Indiana University Purdue University Indianapolis. ASFPM is also grateful to Philip J. Schneider, AIA, Director, Hazards Risk Assessment Program National Institute of Building Sciences for his judicial review and support in maintaining the working relationship between ASFPM and the NIBS.

INTRODUCTION -- METHODS -- HAZUS-MH PROCESS -- Elevation Data Sources -- Riverine Hydrology Sources -- Riverine Floodplain Elevation Determination and Boundary Mapping -- Coastal Floodplain Elevation Determination and Boundary Mapping -- Additional Floodplain Boundary Mapping -- ANALYSIS -- Riverine analysis -- Coastal analysis -- RIVERINE RESULTS -- FLOOD DEPTHS -- Harris County -- Mecklenburg County -- FLOODPLAIN BOUNDARIES -- Harris County -- Mecklenburg County -- COASTAL RESULTS -- FLOOD DEPTHS -- FLOODPLAIN BOUNDARIES -- CONCLUSIONS -- APPENDIX 1: 100-YEAR FLOOD DISCHARGE VALUES -- APPENDIX 2: MAPS OF VALIDATION CROSS-SECTIONS -- APPENDIX 3: MAPS OF VALIDATION TRANSECTS --

The goal of this HAZUS Flood Model validation project was to assess the horizontal and vertical (flood depth) accuracy of the HAZUS generated floodplain boundary. To perform this assessment, ASFPM used the HAZUS-MH Flood Model and boundary delineation outputs and compared against detailed floodplain studies for three (3) pilot areas, which included the following:

Roan Gully and Willow Creek, Harris County, TX
Doby Creek and Mallard Creek, Mecklenburg County, NC
Open and Bay Coastlines, Suffolk County, NY