BKI was contracted by Plaquemines Parish to develop wetland vegetation ridges immediately adjacent to the back levee system between Fort Jackson and Venice, Louisiana as part of the Plaquemines Parish Coastal Restoration Project. The project provided stabilization to the existing area through the infilling of three open water areas that currently penetrate the brackish marsh, adds freshwater nutrients and sediment to assist the improvement of the quality of the existing marsh, and establishes transitional wetland vegetation on the west side of the ridges.
While this project converted over 394 acres of brackish marsh into Roseau Cane and Cypress ridges, the impact was offset by the creation of 582 acres of new brackish marsh through the infilling of open water and the enrichment of an additional 158 acres of existing brackish marsh.
Materials for the construction of the ridges, creation of new brackish marshes, and the enrichment of existing brackish marshes were hydraulically pumped from the Mississippi River, over the main line river levee, under LA Highway 23, and across the Reach B-2 back levee through a 30” pipeline. Permits for dredging in the river, crossing the levees and highway, and placement of dredge materials in wetlands were pursued through the various Federal and State agencies by BKI. BKI also prepared plans and specifications for the hydraulic placement of these materials and provided engineering and design (EDC) and inspection services during this phase of construction.
BKI's first assignment under this contract was part of the Barataria Basin Land Bridge Shoreline Protection Project south of Lafitte, LA. BKI designed approximately 6,100 lf of shoreline protection to reduce or eliminate erosion of a portion of Bayou Perot and Bayou Rigolettes in Jefferson Parish, LA.
Rock dikes or rock rip-rap revetments over woven geotextile fabrics maintained a stable bank and resist erosion and wave action. Plans included placement of warning signs and settlement plates, which monitored movement and stability of the shoreline after construction is complete. The contract included preparation of preliminary and final construction documents, specifications, and construction cost estimates for the proposed improvements.
The final engineering cost estimate for this project was $1,900,000 and the actual construction cost was $1,750,000.
Jefferson Parish Bucktown Harbor Mitigation Marsh
BKI was retained by Jefferson Parish to prepare a Master Plan for the Bucktown Harbor Marina Complex on Lake Pontchartrain in Jefferson Parish. The plan includes a 3.5-acre wetland marsh to improve environmental conditions on the lakeshore.
The Bucktown Harbor permit plan and application process that BKI undertook for Jefferson Parish required a National Marine Fisheries 3.5 acre mitigation marsh. The habitat value of the new marsh offset the lake-bottom loss of the 17-acre land reclamation activities that were implemented to create the marina, and 6 acres of harbor dredging requested in the permit. At the completion of the land reclamation, BKI prepared plans and specifications for the bidding of the wetland plantings for the Spartina alterniflora marsh and did construction administration and monitoring of the plantings.