Evaluation of HAZUS-MH Flood Model with Local Data and Other Program

This paper presents an evaluation of the HAZUS-MH flood model conducted as part of the Harris County Risk Assessment Program completed in November, 2005. The county wide analysis proved the capability of the HAZUS-MH software for a large urban county application. For the pilot watershed study, the HAZUS-MH Level 1 analysis was quick and least costly. However, the loss estimates may be questionable. The Level 2 analysis produced much more reasonable loss estimates than the Level 1 analysis when compared with other detailed analyses. HAZUS-MH Level 2 estimated $179 million for 1% probability event and $286 million for 0.2% probability event building related economic loss for residential properties in White Oak Bayou watershed. This compares well with the results of the Section 211 Federal Flood Control Project: General Reevaluation Report study for the same area of $153 million for 1% and $292 million for 0.2% loss estimates. Both the building damage count and loss estimates from HAZUS-MH Level 2 showed a linear correlation with the Federal Flood Control Project results (R2=0.9997 for building damage count and R2=0.9786 for loss estimate). Based on comparison in this study, a HAZUS-MH Level 2 analysis appears to be a better, more cost-effective approach to achieve reliable results for risks assessment and mitigation planning.