Ship Wave-Induced Sedimentation of a Tidal Creek in Galveston Bay

• Published in: Journal of waterway, port, coastal, and ocean engineering port, coastal, and ocean engineering, 2008-01, Vol.134 (1), p.21-29
• Main Authors: Ravens, Thomas M, Thomas, Robert C
• Format: Article
• Language: English
• Subjects: TECHNICAL PAPERS
• ISSN: 0733-950X; 1943-5460
• DOI: 10.1061/(ASCE)0733-950X(2008)134:1(21)

During the summer of 2005, a tidal creek (“Pine Gully”) within a few kilometers of the Houston Ship Channel was completely blocked by a 200 m long and 1.5 m deep plug of silt and fine sand. This paper documents and explains this unusual sedimentation event. It then presents a new method for calculating ship wave-induced sediment transport into tidal creeks. Between November 2005 and January 2006, measurements of velocity, pressure, and suspended sediment concentration were taken in the creek approximately 150 m seaward of the plug. The data indicated ship wave-induced bores (one per ship). Each bore caused a net sediment transport of approximately 0.4 m3 toward the plug, enough to explain the observed rate of sediment accumulation. Cores of the plug showed that the plug material was consistent throughout, suggesting a single pathway (from the bay). During the period of plug formation, rainfall and creek discharge were relatively low indicating a likely factor for the plugging. Model calculations showed that significant ship wave-induced sediment transport into Pine Gully would occur only when Pine Gully mean depth is less than 0.8 m .