Safeguarding Savannah
G E O W O R L D / N O V E M B E R 2 O O 9 24 Government Special Issue BY REBECCA BLANKENSHIP Local Gover nment T he low-lying coastal plains of Savannah, Ga., are susceptible to severe, continual flooding. Since 1948, Chatham County has flooded more than 14 times due to storms with four inches of rainfall or more, and more than 1,400 dwellings have flooded during those events. To help prevent such devastating occurrences, the city of Savannah recently embarked on a mission to prepare a comprehensive upgrade to its existing Flood Hazard Mitigation Plan with a system, HAZUS-MH, that uses GIS technology. The project's principal goals were threefold: 1. Assess and quantify current flood-hazard risks using new geospatial data and best available technology. 2. Increase public and stakeholder involvement in the city's mitigation planning efforts. 3. Maximize potential credit points under the Federal Emergency Management Agency (FEMA) Community Rating System (CRS) through quality plan development and implementation. Flood Hazard Risk The study used HAZUS-MH, a multi-hazard loss-estimation methodology based on GIS technology (ArcGIS 9.2), to calculate estimated physical damage and functional loss from earthquakes, floods and hurricane wind. HAZUS-MH was developed by FEMA, under contract with the National Institute of Building Sciences, to provide local decision makers with a more complete understanding of the impact these hazards would cause as well as the subsequent mitigation and preparedness measures that local governments should take. HAZUS-MH operates as an extension to ESRI's ArcGIS software to map and display region-specific hazard data along with the results of loss and damage assessments. It also uses Microsoft SQL Server to manage the extensive amount of data generated for a given regional loss estimate. The extension has several complex analysis mod-ules that are initiated through the HAZUS/ArcGIS Citizens and Technology Take Active Role in Flood Mitigation