- Zoning regulation, building code and FEMA and state flooding ordinance review
- Modeled wave and inundation and HAZUS-MH calculated losses.
- GZA GeoTool GIS web application for information management and analysis. Direct interaction with HAZUS-MH functionality and data through web GIS.
Challenge
The Town of Old Saybrook selected the GZA Team to complete an evaluation of existing local, state, and federal programs, plans, and capabilities that will likely be impacted by future conditions resulting from sea level rise, storms urge and increased precipitation.
Solution
GZA’s overall resiliency approach included: 1) use “state-of-the-science” methodologies, including numerical models, for characterizing flood hazards and sea level rise; 2) calibrate our hazard analyses to those developed by the US Army Corps of Engineers (USACE) North Atlantic Coast Comprehensive Study (used for federal projects); 3) utilize HAZUS-MH for estimating losses; 4) present a blend of resiliency recommendations ranging from physical mitigation projects to change to Old Saybrook’s plans, policies and regulations; 5) take an integrated approach for physical mitigation projects including both structures and natural and nature-based features; and 6) use ARCGis for all information management, including our web-based GIS GZA GeoTool©.
GZA also investigated the previous extent of the previous damage from Sandy and other Storms using existing mapping layers within GZA’s Coastal Engineering GeoTool web mapping application. The Assets/Vulnerabilities Inventory and resulting storm surge and wave models are stored and managed in a SQL Server Geodatabase for integration with FEMA’s HAZUS-MH to conduct a Level 2/3 analysis to assist the Town in the ranking of facility importance based the potential economic damages (or consequences) and impact to the community if an asset were to fail. Additionally, all geospatial data developed for this project along with data from FEMA, NOAA, USGS and others is accessible via GZA’s Coastal Engineering GeoTool GIS Web Application and mobile GIS for analysis and identifying potential mitigation project opportunities from the office and in the field.
Geospatial Modeling and Vulnerability Assessment
GZA recently completed the development of a baseline topographic model (Digital Elevation Model (DEM)) for the Town using the highest available resolution LIDAR elevation data. Additionally, GZA identified, inventoried and integrated existing critical facilities infrastructure, essential facilities into our web-based GIS GZA GeoTool©. Our team is in the process of using this unified geospatial platform to conduct the risk and vulnerability assessment throughout the Town of Old Saybrook for multiple flood risk scenarios.