Virginia Coastal Resilience Master Plan (CRMP) Graduated Coastal Flood Extents for the Baseline planning scenario.

Coastal flooding occurs when tidal waters exceed the typical shoreline and inundate upland areas, including both tidal inundation and storm surge. This dataset depicts the extent of potential coastal flooding under various flood conditions. 10-foot resolution raster data is classified and colored to represent the extent of the most frequent (least-rare) floods that may impact a given area. The included flood conditions range from daily high tides to rare storm surge events, with probabilities derived from statistical analysis of historic events. The storm surge events are described in terms of their relative annual exceedance probability (AEP), which represents the percentage chance that a given flood magnitude will occur in a given year. The specific flood conditions included are: Mean Low Water, Mean High Water, 50% AEP, 20% AEP, 10% AEP, 4% AEP, 2% AEP, 1% AEP, and 0.2% AEP.

This dataset contains information for the baseline planning scenario, meaning it is based on historical, observed data and does not incorporate anticipated future conditions. This data is suitable for understanding current conditions (2020) and can serve as a basis for comparison with future conditions.

The CRMP’s coastal flood modeling considered changing relative sea level rise projections based on the NOAA 2017 Intermediate High Curve. Complete documentation of the source data and production process can be found in the VA CRMP Phase I Appendix C – Coastal Flood Hazard Framework Report (Dewberry, 2022).

Related resources include the VA CRMP Master Plan and reports (https://www.dcr.virginia.gov/crmp/) and Coastal Resilience Web Explorer (https://www.dcr.virginia.gov/crmp/cr-web-explorer).

For questions or additional information, please contact Flood.Resilience@dcr.virginia.gov.