Blasting may not be necessary to deepen the Jacksonville harbor to a depth of up to 50 feet, a U.S. Army Corps of Engineers chief announced Thursday.
Eric Summa, chief of the Environmental Branch Planning Division of the Corps Jacksonville District, announced the possibility to about 60 attendees during a presentation at the Jacksonville Port Authority Cruise Terminal at the Dames Point Marine Terminal.
The Corps is studying the environmental effects and a cost-to-benefit analysis of deepening the port’s shipping lanes.
It released preliminary results of the ecological models that are being used for the Jacksonville Harbor Navigation Deepening study, which is evaluating lowering the depth of the channel from its current depth of 40 feet to 50 feet.
The models are being used to help assess potential effects that proposed deepening may have on the St. Johns River ecosystem.
The project received national recognition in July when President Barack Obama included it in his administration's “We Can’t Wait” initiative, an effort to expedite infrastructure projects the administration believes could provide a boost to the national economy.
The designation will help the study be completed a year ahead of schedule, but it still is too early to tell if blasting would be necessary to break through the limestone beneath the St. Johns River.
"We may not even have to blast. Some dredging companies have big enough equipment to break through that material," said Summa.
The preliminary results of the research showed the areas that could be most affected by the deepening of the channel are submerged aquatic vegetation and wetlands.
When studying the deepening of the channel to depths of 44, 46 and 50 feet, the Corps noticed fluctuations in the salt levels of the river between the Fuller Warren and Buckman bridges.
The study includes one of the driest periods for the river, 1999-2001, so researchers can study the river during extreme conditions.
"All the information doesn't exist yet for these models, so some assumptions have to be made. We want to make sure that those assumptions are realistic," said Lisa Rinaman, St. Johns Riverkeeper.
The Jacksonville Port Authority is partnering with the Corps to conduct the study. The port is preparing for the completion of the expansion of the Panama Canal in 2015 and the larger post-Panamax ships that will come through it. Though the port already is serving post-Panamax ships, it cannot dock at local ports fully loaded because of the channel depth.
"No one is more concerned about balancing the environmental aspects of this than the Corps and the port. We are not going to sacrifice the environmental situation we have here in Northeast Florida for economic reasons, there has got to be a balance," said Chris Kauffmann, chief operating officer of the port.
The preliminary results of the ecological models will be available to the public at the Corps' website, www.saj.usace.army.mil.
The next public teleconference will be Dec. 3. Information also will be on the website.
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