This report has been developed in response to Item 451 (D) of Chapter 1 of the 2023 Special Session I Acts of Assembly (the “Appropriation Act"). The Appropriation Act directed the Virginia Department of Transportation (VDOT or the “Department"), with the assistance of the Virginia Institute for Marine Science (VIMS), to provide an annual update on the status of the “Coastal Virginia Transportation Infrastructure Inundation Study" including: an up-to-date identification of at-risk rural, suburban and urban infrastructure, and planning and options to mitigate or eliminate the identified risks; and a report on what work remains to be completed and estimated time frame for the completion of its work.

In 2019, VDOT’s Virginia Transportation Research Council (VTRC) entered into an agreement with VIMS requesting that VIMS conduct a five-year study to develop a strategy for understanding and addressing sea level rise, land subsidence, and recurrent flooding impacts on existing and planned road infrastructure, as well as how that infrastructure will impact natural ecosystems in Virginia’s coastal zone as the climate changes (the “VIMS Study"). This report summarizes the overall cumulative progress of the VIMS Study, provides an update on significant findings made since the submission of last year’s report in December 2022 (“Study Year Four"), and identifies how data from the VIMS Study is being incorporated into VDOT’s statewide resilience planning efforts to manage identified risks to transportation infrastructure.

In the most recent Study Year Four, VIMS continued development of a network flooding analysis that measures the inaccessibility of road networks based on flooding intervals of 6-inch increments, up to 10 feet of inundation. In its initial phase, VIMS conducted the network flooding analysis for approximately 11,000 miles of roadway in the south Hampton Roads (Peninsula and Southside) region, with 19 VDOT facilities selected as priority destinations or “Source Points." VIMS included an additional 13 VDOT facilities as Source Points and 7,163 miles of roadway in the Peninsula and Eastern Shore regions to the network flooding analysis in Study Year Four. VIMS also continued to build the interactive viewer by integrating the results from the flood hazard zone assessment, the completed network flooding analyses, and pertinent VDOT infrastructure information. In addition to the impacts of a changing climate on existing and planned road infrastructure, VIMS continued their work on examining the impacts of road infrastructure on the natural ecosystems in Virginia’s coastal zone. Once VIMS has completed its work on the flood hazard zone assessment, network flooding analyses, and the infrastructure interactive viewer tool, the appropriate options to mitigate or eliminate identified risks may be selected and implemented by decision-makers in conjunction with VDOT’s Resilience Plan which was published in December 2022, and serves as a roadmap to incorporate a framework of resiliency principles in the Department’s transportation planning, project development, delivery, operations, maintenance, and asset management efforts.

The anticipated completion date of the VIMS Study is September 2024. The remaining work includes expanding network flooding analyses for the remainder of Virginia’s coastal area beyond the south Hampton Roads (Peninsula and Southside) region, Eastern Shore, and Planning District 8. VIMS will also add a network flooding analysis using hospitals and emergency medical facilities as destination points. VIMS will continue further to incorporate new data from the network flooding analyses and other identified planning requirements into the interactive viewer.