The purpose of this study is to assess how the deposition and mobilization of Hurricane Harvey (2017) flood deposit and elevated subsidence has impacted sedimentation within Galveston Bay. The Bayport Flare/Channel, located with the San Jacinto Bay (SJB) portion of the northwestern corner of Galveston Bay, has experienced a 25% (6.25% annually) increase in siltation since Hurricane Harvey (2017).
The floods associated with Harvey deposited 131.34×106 tons of sediment in Galveston and in the four years after Harvey, 27% of the deposit has eroded, increasing the bay’s suspended sediment load by 9% annually. SJB has subsidence rates of 1.5-2.2 cm y-1 and has an average sedimentation rate of 2.6 cm y-1, indicating that SJB is a net sediment sink. Sediment Trend Analysis (STA) was performed on a grid of sediment grab samples from the SJB area and reveals sediment transport convergence from all sides of SJB, with the dominant pathways from the most exposed portions of Galveston Bay to the south and southeast. This study concludes that the elevated siltation within the Bayport Flare/Channel is likely sourced from the eroded sediments sourced from the Hurricane Harvey flood deposit within Galveston.