PLEASURE ISLAND SHORELINE PROTECTION PROJECT

摘要

Pleasure Island (PI) is located in Jefferson County, Texas, across the Sabine-Neches Canal (SNC) from Port Arthur. The approximately 6-mile-long shoreline has sufferedsignificant erosion due to several unique factors. First, the island was created from dredgedmaterials containing weakly consolidated soils primarily of silty clay with some sand thatprovides little resistance to erosion. Second, significant vessel traffic in SNC continuouslygenerates waves that attack and erode the shoreline. Over the years, various types ofshoreline protection structures have been implemented on several sections of the shorelinebut erosion continues. Some existing structures have failed and created another dimensionof complexity in the effort to stabilize the shoreline.The Texas General Land Office (GLO), as authorized by the Texas Coastal ErosionPlanning and Response Act (CEPRA), funded the project. Jefferson County, Texas, actedas the local sponsor for this project. The objective of the project was to protect the existingshoreline from further erosion, which would eventually threaten the T. B. Ellison Parkway, thesole access road to PI.This paper presents the efforts and challenges involved in the project. A significantdata collection effort was conducted to understand the issues and formulate solutionalternatives. These efforts included a determination of the historical shoreline erosion rate;a bathymetric and a shoreline survey; a side-scan sonar survey to identify submergedstructures and their distribution; a structure survey to identify the location, extent, andconditions of existing visible structures on the shoreline; and a geotechnical survey to identifysoil composition along the shoreline. Based on the findings, a set of shoreline stabilizationalternatives was developed and recommended. Considering project schedule and otherfactors, GLO and Jefferson County then selected a set of suitable alternatives. Constructionof Phases 1 and 2 was completed in the fall of 2001. Construction of Phase 3 is underway,with completion scheduled for winter 2002.