Nassau County Federal Shore Protection
*Update - 3/18/09:
Request for Quote: Beach Tilling Services
“Update – 10/23/08:
Beach Changes - What to expect in the coming months
The recently constructed federal beach restoration project placed approximately 1,800,000 cubic yards of sand along nearly 3.8 miles of City of Fernandina Beach shorefront. Irrespective of its size, the base beach authorized by Congress and designed by the U.S. Army Corps of Engineers is only 40-ft wide at an elevation of +10-ft above sea level (see Figure 1). Albeit much wider than pre-project conditions, it is not overly large for a beach fill project. Moreover, the project is designed to be renourished (or maintained) every five years. This portends that at the end of five years, the beach should have reached (on average) its 40-ft design dimension. At that time, sufficient additional sand must be again placed to protect the design beach template for another five years.
To facilitate cost effective construction, dredged material is initially placed as a very wide fill berm. Most of this sand however, is not expected to end up as dry beach. The reason is that the actual beach profile intended to be improved extends from the dune (or rock revetment) seaward to water depths of 20-ft or more, a 1,000 feet offshore (see Figure 2). That is to say, the sand that is initially placed as a construction berm will move offshore to deeper water in order to form the natural foundation for the new beach. This movement occurs principally during periods of high wave energy – namely nor’easters and tropical storms. The more energetic the storm season – the quicker the equilibration process will proceed.
As a result of this process, the water’s edge along the construction berm (or mean high water line) appears to move extremely rapidly in a landward direction. Often, this transport of sand from the berm to the seaward portion of the beach profile is construed as a form of “project failure”. Instead, however, it is an expected part of the beach equilibration process. Accordingly, it is important to realize that what one initially sees after construction is not the design beach. The final beach width and residual slopes – as shaped by Nature – generally takes between 6- and 24-months. The City of Fernandina Beach fill project has been affected by both Tropical Storm Faye and normal nor’easters that typify northeast Florida beginning in the month of October. As expected, the constructed beach berm has therefore been “adjusting” rapidly. Similarly, the vertical beach “scarps” that occur along the newly placed sand berm are a predictably frequent occurrence during the first year or two of the project life, and these must be periodically removed by mechanical means to keep the beach user friendly. It is likewise important to understand that in the future the new beach will again be subject to seasonal changes. Winter beaches will be narrower due to storms, but summer beaches will be wide and more robust as sand moves landward during periods of low wave energy.
Fortunately for the City of Fernandina Beach, sand dredged from the St. Mary's Entrance Navigation Channel is routinely placed at the north end of the City limits every several years. The cost for this effort is borne by the U.S. Navy. Although the volume varies significantly from year to year, this additional sand added to the littoral system should serve to improve the beach restoration project’s long term performance and ideally extend the number of years between project renourishments.
Figure 1
Figure 2
View Past Updates
Project Information
The Nassau County Federal Shore Protection Project will be constructed along Fernandina Beach in the summer of 2008. The project will widen and restore the sandy beach along 4-miles of shoreline from Fort Clinch State Park to just south of Sadler Road. To accomplish this, about 1,725,000 cubic yards of sand will be dredged from the seabed about 3-miles offshore, pumped through a temporary pipeline, and placed on to the beach.
Construction of the project is currently anticipated to begin in late June, and to take about 3 to 4 months to complete. Beginning in late May, before dredging and beach fill placement starts, construction equipment and sections of pipeline will begin to arrive for staging upon the beach.
The “fill area” for sand placement extends from about 600 north of the State Park boundary (Kimberly Street) to about ¼-mile south of Sadler Road. The sand placement and beach construction is expected to be completed in four consecutive segments, in order:
- Starting near about 2nd Street (north of Dolphin Street) and proceeding north to the Park boundary,
- From 2nd Street southward to about ¼-mile south of Atlantic Avenue (near Ohio Avenue),
- From about ¼-mile south of Jasmine Street northward to Atlantic Avenue,
- From about ¼-mile south of Jasmine Street southward toward Sadler Road.
The actual locations or sequence of the construction process might vary.
The “borrow area” from which the sand will be dredged is located about 2 ½-miles from the St. Mary’s River Entrance mouth, and between about 1/3 and 1-mile south of the navigation channel. (That’s about one mile seaward of the jetties, south of the #19 green buoy). Dredging for the project will deepen the seabed at the borrow area from about 20~30 feet to about 35 feet depth.
The dredged sand will be pumped through a 30-inch diameter pipeline that is temporarily placed upon the seabed and onto the beach. The sand is pumped with seawater to carry it through the pipe. When the mixture of sand and water is discharged from the end of the pipe, the sand drops onto the beach and the water flows back to the sea. Bulldozers push the sand to shape the new beach. When a section of beach is completed, more pipe is added and the filling and shaping process continues along the shoreline.
The sand placement will initially raise the elevation of the beach by several feet and will widen the beach by between 50- and 150-feet. The width and volume of sand placement will vary along the shoreline, depending upon the local condition of the beach. Filling will not occur landward of the existing dune; but exposed sections of rock revetment will be buried with sand.
Within a few months after the sand is placed, the width of the new beach will have decreased by about half of its initial width, depending upon the year’s storm activity. This process, called “equilibration”, is the natural result of the waves and currents moving the sand from its constructed shape to a more natural shape. (Nature is more efficient at accomplishing this adjustment than man’s machines, and so the sand is initially placed upon the upper beach for the ocean to re-work). The initial placement, and subsequent equilibration, of the sand will result in a wider intertidal beach than presently exists.
As construction progresses along the shoreline, portions of the beach will be temporarily closed. For purposes of safety, about 1000-feet of beach is closed to all public access and recreation in the immediate vicinity of the pipeline’s discharge. As the construction activity passes, the beach is re-opened. Usually, any one area of beach is only closed for two or three days, at most. Where the pipeline must remain on the new beach for a few weeks longer, small sand “ramps” will be constructed to facilitate pedestrian crossing over the pipe.
Because the cost of the dredging equipment and crew is large, and in order to complete the work as soon as possible, the beach construction will occur 24-hours per day, 7 days per week. The construction will typically progress along the beach by about 150- to 250-feet each day. People who live or are visiting near the beach will hear the construction activity for several days as the work passes along their area of the shoreline. For safety reasons, and by federal law, the bulldozers and other construction vehicles must operate audible “beeper” alarms when they back-up. These beepers cannot be turned off.
The work involves very large marine construction equipment, floating and submerged pipelines, high-pressure discharge of sand and water, and heavy construction vehicles. Both the dredging and beach fill work areas can be very dangerous, and it is extremely important that persons not involved with the construction stay clear of the work areas. This includes boaters, swimmers, people walking on the beach (and their pets), shell-collectors, residents and visitors.
Because the construction will occur during the marine turtle nesting season, the beach will be monitored early each day for sea turtle activity, and the contractor has certain restrictions for night-time operations. The work also requires that environmental monitoring is conducted for sea turtles in the water, as well as other animals, shorebirds, and seawater turbidity.
The project is managed and contracted by the U.S. Army Corps of Engineers, Jacksonville District. The Contractor is Weeks Marine, Inc. The City of Fernandina Beach is the project’s Local “non-federal” Sponsor and Permittee. Olsen Associates, Inc. is the City’s coastal engineering consultant.
The project’s contract construction cost is about $14.1M. About 79% of the project cost is funded by the federal government, and about 10% is funded by the State of Florida Department of Environmental Protection, and the remaining 11% is co-funded by the City of Fernandina Beach and Nassau County. The federal shore protection project was originally authorized by the U.S. government in 1986, but this will be the initial construction of the project.
Previous beach fill work along portions of this shoreline have included the placement of sand dredged from the navigation channel at the St. Mary’s River Entrance. The overall nature of that work is very similar to the beach construction that will occur this summer. The primary difference is that the 2008 beach fill project is being specifically constructed by the Corps of Engineers to improve storm protection and to re-build and maintain the beach along northern Amelia Island.
As construction begins and the work moves along the beach, this website will be updated to provide the latest available information about the project’s program, schedules, and other items of public interest.
For questions or additional information about the project, contact:
Mr. Jim Vecchitto (U. S. Army Corps of Engineers),
Office (904) 232-3808, or Cell (904)-607-5847
Early Stages
August 9th (Main Beach)
August 13th
August 23rd (Un-nourished/Filled shoreline)
October 25th (Escarpment Removal)
