Posted on June 11, 2019
The federal government is taking a new look at curing North Jacksonville’s dying Fort George River inlet, which is choking on an enormous amount of trapped sand that could one day dam the tidal river from the Atlantic Ocean.
The inlet’s troubles are well-documented, as are the associated threats of erosion to Little Talbot Island, which is home to a state park and hurricane evacuation route, and diminished water quality for tens of thousands of acres of marsh that make up the Timucuan preserve.
Still, local and state officials have all but ignored the problem since City Hall failed to get federal money to dredge the inlet more than a decade ago.
But thanks to the persistence of a local engineering firm working on behalf of the Florida State Parks – Little Talbot Island State Park has already lost a pier, parking lot and stretch of shoreline to erosion – the United States Army Corps of Engineers expects to begin studying the problem later this year, a crucial first step towards approving a dredging project that could be mostly paid for by the federal government.
“We’re gratified that it appears to be moving ahead,” said Erik Olsen, the principle of the engineering firm, Olsen Associates.
The Fort George River begins at the Intracoastal Waterway, running about five miles along the southern end of Little Talbot Island before emptying into the Atlantic Ocean a few miles north of the St. Johns River.
The river is a popular sandbar destination for boaters, and it’s also a major artery of ocean water for the area’s vast marsh, a rich ecosystem finely tuned to the daily ebb of the tide.
These days, the Fort George River is sick with sand, one of the many unintended consequences of the extensive work that went into creating a deep-water port in Jacksonville’s St. Johns River.
The culprit is the north St. Johns River jetty, which impedes an underwater river of sand that travels south along the coast of Florida. With nowhere to go, the sand has long accumulated north of the river, and a great deal of it has become trapped in the Fort George River’s inlet.
Like a congested artery, the sand has narrowed the river’s mouth and restricts the amount of water that can move through it. This condition has created a domino effect that traps sand upstream, clogging the river’s channels and in some cases, completely filling them in.
Meanwhile, the sand is also forcing the river’s mouth to creep ever north, resulting in erosion that is eating away at Little Talbot Island. More damage could occur if the inlet isn’t fixed.
The sand deposits in the inlet are also a ticking time bomb. Engineers say that during a perfect storm, the sand could get swept into the river’s narrow mouth and completely fill it in, which would stop the river’s tidal flow dead in its tracks.
Although the exact consequences of such a situation are unknown — experts say they aren’t aware of a similar scenario happening in the southeastern United States — it would almost certainly disrupt the tidal ecosystem.
“It would have major ecological consequences,” said Chris Hughes, superintendent of the National Park Service’s Timucuan Ecological and Historical Preserve. “This ecosystem relies on the daily flushing through that inlet. That transfer of water is critical… As responsible stewards, we are very concerned about what the potential impacts could be.”
• • •
The engineers who set out in the late 1800s to clear the maze of ship-sinking sand bars from the St. Johns River’s inlet and carve a shipping channel learned a tough lesson: No matter how much they dredged, the ocean quickly erased their progress by filling everything back in with sand.
They worked around this problem by piling granite and limestone on the north and south ends of the river, the early foundations of the jetties that today extend a mile into the ocean.
The rock walls were a game-changing development in the nascent city’s quest to build a deepwater harbor, protecting its newly dug channel from intruding sand on either side.
However, a new generation of engineers later would learn new lessons about the law of unintended consequences.
As city leaders sought deeper water, the Army Corps outfitted the jetties with a concrete cap, filling in cracks and crevices that still allowed sand to infiltrate the wall and settle into the St. Johns River channel, where it would have to be removed by expensive maintenance dredging.
The concrete cap proved to be exceptionally effective. In fact, it worked so well that it ceased the natural southward flow of sand down the coast, the ocean’s intrinsic way of replenishing beach erosion. That function is now performed by costly projects at the expense of taxpayers.
With nowhere to go, the sand that had always migrated south began backlogging at the foot of the north St. Johns River jetty.
• • •
After engineers capped the jetty, the backlogged sand created a new land mass — today, it’s the home of the city’s beachfront Huguenot Park — and began pushing the mouth of the Fort George River north.
By the late 1970s, the mouth of the river was eroding southerly parts of Little Talbot Island, forcing the state to build a rockwall along the river to prevent parts of State Highway A1A, a hurricane evacuation route, and the bridge that took drivers across the Fort George River from being swept away.
Erosion problems resurfaced in the late 1990?s, destroying a wooden pier and parking lot on Little Talbot Island State Park and rendering the A1A bridge unusable. State officials considered rerouting the state highway to avoid the menacing river crossing altogether, although they later decided to rebuild the bridge in the same location
While costly, erosion wasn’t the only threat lingering in the choking inlet.
In a 1999 study of the river’s inlet, Olsen Associates, the engineering firm working for the state parks, concluded a powerful storm could move the large deposits of sand trapped in the inlet into the only remaining part of it that was connected to the ocean, resulting in either a partial or full closure of the river.
If that were to happen, the engineers predicted the marshes receiving water from the Fort George River’s tidal flow would be left with whatever water made its way from the Nassau Sound and St. Johns River, a “significantly lower quality” water that could be contaminated with industrial pollutants from a major shipyard located at the intersection of the St. Johns River and Sister’s Creek.
Twenty years and a handful of hurricanes later, the inlet hasn’t closed yet, although Olsen said the scenario remains a possibility.
“We’ve always assumed it would be a hurricane with the right duration, right angle, right wind activity. They’re just so different,” he said.
• • •
As islands of sand formed around wooden channel markers in the mid-aughts, Olsen Associates had drawn up a plan to dredge the inlet.
The seemingly straight-forward approach would not only restore water flow to river and fend of erosion, but it also delivered the tangential benefit of providing a sorely needed source of sand for a beach renourishment project that was underway on Duval County’s southern coastline.
City Hall lobbied the federal government to authorize the project for several years, but the Army Corps dealt the project a fatal blow after it determined it was too costly to transport sand from the inlet to the beaches they were rebuilding.
After that effort failed, the problems at Fort George seemed to slip from everyone’s mind.
Case in point: When the Times-Union requested an interview with city officials in late 2018, a spokeswoman said nobody could find anything about the problem or any current efforts to fix it.
Every few years, Olsen’s firm raised the issue with the city or state, but nobody bit, which he attributed to tight budgets, short memories and higher priorities.
“And no screaming need,” Olsen said. “We can’t even address flooding in San Marco. This is tertiary compared to that.”
Olsen added: “This isn’t on anybody’s radar. You have to put it there.”
After a few decades of trying, Olsen’s firm managed to do that.
• • •
A few years ago, Olsen and his colleagues made another push to fix the Fort George inlet. This time, they set their sights on a special Army Corps program designed for smaller projects that don’t require congressional authorization.
Like their previous attempts, it seemed like another long shot; neither City Hall or the Parks Service had any interest in sponsoring the project.
The firm instead applied for money on behalf of the South Amelia Island Shore Stabilization Association, a nonprofit that hoped to use the sand dredged from the inlet to renourish its beaches.
This time, the application gained the Army Corps’ attention.
The project cleared an initial step in the approval process earlier this year, and it soon earned another break when the state parks stepped up as a sponsor, which simplifies the approval process.
Now, the state parks and Army Corps are negotiating a payment agreement for a feasibility study, which is the next major hurdle the project must pass.
In order for the project to move forward, the feasibility study must find that the construction of the jetties resulted in the river’s problems, and that dredging it would be a highly effective and reasonably priced solution.
It’s unclear how the project will rank in the latter category, although officials are confident it will clear the first benchmark. If it does, 98 percent of the project’s cost would be paid for by the federal government, up to $9.8 million.
An Army Corps spokeswoman said the study could begin this fall and will likely take a year to complete.
Olsen said he’s cautiously optimistic about the recent developments, and he credited the Army Corps for considering a project that had been ignored for so long.
“It is a long shot. It’s a weird duck,” he said. “I will say that the (Army) Corps is trying to accommodate everyone’s interest here. They have a unique program that they’re going to try to fit this into. A lot of credit goes to the Corps for trying to make the shoe fit the right foot.”
Source: jacksonville.com
