Mapping Maryland's Inundation Zones

ABSTRACT ONLY - Many Marylanders are unaware of the States dam portfolio and have even less of an understanding of the consequences of dam failures. The Maryland Dam Safety program has historically struggled with balancing the desire to share information with potentially affected populations with protecting critical infrastructure from nefarious actors. Fortunately, postures have changed to favor information sharing to generate an informed and prepared citizenry.
This change in posture has allowed the program to begin sharing dam locations along with relevant information via Google Earth and ArcGIS Online and inspired an application for a FEMA Hazard Mitigation Grant to develop and share inundation mapping for all dams. To ensure consistent methodologies and products, DSS-Wise Lite was selected as the tool to complete the work. Failure scenarios include normal pool and brim-full analyses, and 1-meter resolution terrain data was used to enhance the finished product.
The benefits of this project, which is on track to be completed in early October 2022, are many. Not only is the Dam Safety program able to perform enhanced outreach activities to show citizens where dams are located in their communities, but the mapping is being displayed on the Maryland digital flood insurance rate maps portal to encourage homeowners outside of the traditional floodplain to purchase flood insurance. The program will also use the DSS-Wise Lite Human Consequences (HCOM) module to screen for hazard creep, and will be leveraging GIS to generate lists of critical infrastructure within the inundation area to be included in Emergency Action Plans and emergency exercises. Lastly, the program intends to use the inundation mapping data to advance Maryland's Environmental Justice initiatives, by enhancing public notice opportunities, emergency action planning and inspections in historically underserved communities.