Freeport LNG has completed the final steps of its Wetland Creation Project along the northern shoreline of the Intracoastal Waterway (ICW) at the gas liquefaction facility on Quintana Island, Texas. It is adjacent to the similar, innovative and very successful wetland creation effort completed several years ago during the construction of the original regasification facility. Both were designed to create natural saltmarsh areas using a cordgrass called Spartina alterniflora, planted behind a wave barrier along the project’s shoreline on the ICW. These areas not only impede erosion from constant barge traffic but also act as a barrier to any potential damage from storms, wind and tidal-driven currents. "What FLNG is constructing is currently referred to as a 'living shoreline,'" states Mike Cassata, Regulatory Compliance Specialist for Freeport LNG. "It also satisfies our wetland mitigation activities, replacing the area that was required for the new dock 2 basin expansion."
The project's pathway has followed a complex series of steps that will culminate when the Spartina fully matures and exhibits its maximum soil cohesion and robustness. This will take approximately two years. The first actions consisted of acquiring two special work permits: one from the U.S. Corps of Engineers for wetland impacts and mitigation, and a second from Texas Parks and Wildlife for Spartina removal and reintroduction.
Next was the creation of the wave barrier, positioned 85 feet from the project’s northern shoreline and extending into the ICW. The barrier encompasses all 11 acres of the wetland creation areas. To build it, a special geofabric material was placed at the bottom of a pyramid-shaped rock barricade, using larger rocks for the initial layers, to a height of three feet above mean sea level. The area was then filled with the material that was dredged while creating the new construction and aggregate docks and stockpiled at the newly established onsite placement area near the east end of the property. The properly dewatered material, approximately 800 dump-truck loads, was brought to the mitigation site, placed behind the wave barrier and leveled to an elevation of about mean sea level. Proper elevation was critical to ensure Spartina growth. During the earlier regasification site work, a line of rock-filled gabion baskets was used to construct the wave barrier. The new construction design was chosen because the wave barrier is located in deeper water.
With the area now ready for planting the Spartina, plants were borrowed from existing wetlands located east of the pretreatment facility and carefully handpicked by an experienced crew. The Spartina was bundled and placed on a boat to be transported to the liquefaction facility. The Spartina sprigs were then planted by hand from airboats, each plant approximately three feet apart. Over 50,000 sprigs were planted. Spartina is a very hearty plant and grows well in the Gulf Coast area. It stands up well to both storms and tidal movement. Its elaborate root structure helps hold sediment intact, reduces erosion and provides habitat for many marine organisms, such as fish and shellfish, and consequently for many bird species.