Project Description
The anticipated 2015 completion of expansion works at the Panama Canal will allow larger ships to transit between Asia and the U.S. east coast. This event provides a unique high-economic-value opportunity for the Jacksonville Port to become one of the few ports on the U.S. east coast capable of serving the larger ships traversing through the canal. Monetizing this opportunity requires expansion of the federally authorized Jacksonville Harbor Navigation Project. To that end, the U.S. Army Corps of Engineers (USACE) Jacksonville District has been working with the local sponsor — the Jacksonville Port Authority — to develop and implement the National Economic Development alternative, the channel redesign which produces the highest net benefit to the nation.
During the course of its studies, USACE enlisted the assistance of Taylor Engineering multiple times as the project evolved from a general reconnaissance/planning phase in 2009 to the complex plan formulation process — documented in a General Reevalution Report (GRR) and an Environmental Impact Statement (EIS) — that was completed in 2014. The plans investigated depth alternatives ranging between 40 and 50 feet from the river mouth upstream a distance of 20 miles.
In the first task order, Taylor Engineering collected wave, current, water surface elevation, and salinity and suspended sediment concentration data with a variety of mobile and stationary measurement instrumentation — side- and bottom-facing ADPs, ADCPs, ADVs, water level gages, CTDs, and LISST. The instruments deployed for periods ranging from six to 90 days. These data supported the calibration of numerical models for circulation, salinity, sediment transport, and ecological parameters. In a succeeding task order, Taylor Engineering applied the ADCIRC model to develop and provide oceanic and estuarine boundary conditions for the use of nearshore models RMA, CMS, and EFDC.
In response to later requests from USACE, Taylor Engineering conducted hydrodynamic and salinity modeling with the Environmental Fluid Dynamics Code (EFDC) model (a refined and recalibrated St. Johns River Water Management District model [SJRWMD]), ecological modeling with tools developed by SJRWMD, and water quality modeling with the CE-QUAL-ICM model. These models provided information for inclusion in the Jacksonville Harbor Navigation Project GRR Phase 2 and EIS. The modeling effort provided the means to assess the direct impacts of channel modifications on river salinity and the cumulative impacts of other factors, including the U.S. Navy Mayport Deepening Project, Mile Point Improvement Project, other navigational improvements, sea level rise, and freshwater withdrawals from the St. Johns River. The domain of the EFDC model encompassed the lower St. Johns River and adjacent Atlantic Ocean. The study area also included Chicopit Bay, White Shells Bay, Mill Cove, major tributaries, and sections of the Intracoastal Waterway, and extended about 120 miles upstream through Crescent Lake and Lake George. Taylor Engineering refined the EFDC model mesh to provide improved resolution in the federal channel to capture channel modification alternatives accurately. Results from the EFDC model provided input for ecological models to evaluate channel modification effects on plankton, submerged aquatic vegetation, wetlands, benthic macroinvertebrates, and fishes and for the CE-QUAL-ICM to estimate effects on dissolved oxygen and chlorophyll.
Taylor Engineering developed and applied a fine-grid MIKE21 model to assess channel modification effects on salinity in numerous salt marshes and river tributaries — Timucuan salt marsh, Ortega River, Cedar River, Julington Creek, and Durbin Creek.
Proudly, Taylor Engineering met the accelerated schedule, the Chief of Engineers signed the Jacksonville Harbor Deepening Project report, and the U.S. Congress authorized the project as part of the Water Resources Development Act of 2014.
