Sabine Pass to Galveston Bay Coastal Storm Risk Management

Forgen undertook this project as part of the Coastal Storm Risk Management (CSRM) Program, aiming to reduce the risks of storm surge impacts from hurricanes and tropical storms. The goal was to enhance the performance and resilience of the existing Port Arthur and Vicinity Hurricane Flood Protection Project (HFPP) in Jefferson County, Texas. Significant heavy civil construction efforts were required to repair levee embankment slope failures while adhering to a 500-linear-foot limit on levee degradation during hurricane season, necessitating effective erosion control and levee infrastructure construction. 

Our work included installing perimeter fencing, conducting geotechnical evaluations, and designing the Deep Mix Method (DMM) mix. We secured approval for a Temporary Flood Protection Plan (TFPP) and adhered to the 500-linear-foot limit on levee degradation during hurricane season. We employed various soil stabilization methods, including in-situ soil mixing, to strengthen the levee. Using multi-auger equipment, we mixed cementitious grout with in-situ soils, creating overlapping columns that formed shear panels and ensured embankment stability for the projects levee raise and future modifications. Additionally, we utilized alternate mix design incorporating Portland cement and Granulated Ground Blast Furnace Slag (GGFBS) to stabilize underlying soil conditions. 

We mixed 67,755 cubic yards of marine clays to a depth of 38 feet, achieving a minimum strength of 120 psi and a hydraulic conductivity of 1 x 10^-6 cm/sec. The total levee degradation covered 1.1 miles, involving the excavation of 68,000 cubic yards and levee restoration of 94,000 cubic yards. We carefully planned and scheduled work to coincide with both levee degrade and levee restoration during hurricane season, adhering to the 500-linear-foot degradation limit. Advanced geotechnical evaluations ensured minimal disruption to the levee’s structural integrity. The use of the Deep Mixing Method and other soil stabilization methods provided a robust solution, mitigating the risks of further failures and creating a strong foundation for future levee enhancements.  

Additionally, Forgen performed work in four offsite areas that were damaged by Hurricane Harvey.  This work included levee degrade, embankment, access road restoration and final seeding. This comprehensive approach to levee infrastructure construction and significantly improved the region’s ability to withstand coastal storm impacts, ensuring the protection of Southeast Texas communities from future storm surges and future flood protection modifications. 

By enhancing coastal resiliency, Forgen has significantly contributed to the protection and safety of Southeast Texas communities, making them more resilient to future storm surges.