Reworking and filling of an ephemeral barrier island inlet formed by Hurricane Beryl, 2024, Texas

Inlets cutting barrier islands, natural or man-made, can alter the impact hurricanes have on marshland, estuaries, shipping ports, fishing industry, and homes, yet their formation is incompletely understood. On July 8th, 2024, category one Hurricane Beryl made landfall at East Matagorda Bay creating a new inlet on the Matagorda barrier peninsula, 2.2 km southwest of the man-made Mitchell’s Cut, and 2.3 km northeast of a closed natural inlet, Brown Cedar Cut. Storm surge from the hurricane created a large overwash fan crossing the entire peninsula and depositing sand in the bay. After landfall, changing wind direction drove a seaward directed surge with the resulting outwash reworking the fan, eroding some of the newly deposited sediments, and further widened the inlet. Following passage of the storm, the newly formed inlet changed in size and shape monthly, initially pointing towards the channel remaining open, but by December 2024 the inlet was filled almost entirely with sediment, and as of January 2026, there has been minimal change in its shape. This study focuses on determining the dominant processes that kept the ephemeral inlet open and the processes that eventually closed it. Preliminary data show storm surges and high-water levels during the 2024 hurricane season kept the inlet open, but sediment transported via longshore currents and wave-action closed it once hurricane season was over. The creation of this ephemeral inlet and its sensitivity to day-to-day processes may alter how future storms and hurricanes impact the barrier island and estuary of East Matagorda Bay.