17 Jul 2025

Overview of the Coastal STORM (CSTORM) Model Development for the Swan Island Restoration Study

Abstract: This document summarizes the numerical model development and validation approach used to simulate the winds, waves, and water levels observed at Swan Island during two prominent historical storm events in the region: Hurricane Sandy and Hurricane Isabel. Using the Coastal STORM (CSTORM) Modeling System, which couples the Advanced Circulation (ADCIRC) and Steady-State Spectral WAVE (STWAVE) models, the North Atlantic Coast Comprehensive Study mesh and grid were refined in the area surrounding Swan Island. The nodal attributes of the ADCIRC mesh in the area surrounding Swan Island were updated to reflect the location of submerged aquatic vegetation around the island. ADCIRC-modeled water levels were in acceptable agreement with observed water levels during both storms, though peak water levels were slightly underpredicted. Similarly, STWAVE captured the phase and trends of the significant wave heights during the storm, while slightly underpredicting both significant wave height and peak period. The validated model will be used to investigate the effect of the restoration of Swan Island on the surrounding area. The results will help to develop guidelines for best practices in island restoration within the Chesapeake Bay and beyond.