BORROW SITE EXCAVATION IMPACTS ON SEDIMENT TRANSPORT ALONG THE GULFSTREAM PIPELINE, PETIT BOIS PASS, ALABAMA

Two borrow sites offshore of Petit Bois Pass in coastal Alabama had been identified as a source of 12.2 million cubic meters (mcm) of sand for the restoration of Ship Island (Mississippi). After preliminary design of the borrow sites, a natural gas pipeline was found to pass through the area of planned excavation. Rather than abandon the plans for the affected site altogether, it was decided to investigate the viability of modifying the original plan by leaving an undredged buffer along the path of the pipeline. A 2D sediment transport analysis was performed to estimate the magnitude of impacts to the pipeline from dredging at both borrow sites using a modified dredging plan that includes this buffer.