Case Studies

Impact of Sea-Level Rise on Roadway Flooding in the Hampton Roads Region, Virginia

Abstract

This study determines the most critically vulnerable major roadways in Norfolk and Virginia Beach, Virginia. Sea-level rise predictions are combined with the mean higher high water and 99% tidal datums and storm surge predictions to project flood water surface elevations through the year 2100. LiDAR data are used to compare major roadway elevations with the projected flood water elevations to determine which roadway segments would be flooded under different scenarios. Traffic data are used to determine critical road segments in the region (heavily traveled and low elevation). Results suggest that by the year 2100, and assuming intermediate sea-level predictions, approximately 10% of major roadways will regularly flood at high tide and 15% will flood at the 99% tide; this increases to more than 65% given a 100-year storm surge event. Five critical road segments are identified that would recurrently flood at high tide by 2100. These road segments should be the focus of infrastructure investments to improve the resiliency of the transportation network within the cities.