Corps of Engineers announces Mile Point contract award
Jacksonville, Fla. – The
U.S. Army Corps of Engineers, Jacksonville District awarded a Mile Point Training
Wall Reconfiguration contract today to Manson Construction Company of Seattle,
Wash., for $39,520,500. The
project will help improve navigation on the St. Johns River, increasing commerce
efficiencies. Added project benefits
include restoring local, historic channel flow and increasing marsh habitat by up
to 34 acres more than the mitigation requirement.
Located on the St. Johns River
near Mayport, the Mile Point project combines relocation and reconfiguration of
an existing stone (training) wall, restoration of Great Marsh Island, and creation
of a flow improvement channel in Chicopit Bay.
The Corps estimates construction will take 12-18 months
with completion anticipated in the winter of 2016.
The Mile Point area limits navigation during
ebb tide due to difficult cross-currents at the convergence of the St. Johns
River with the Intracoastal Waterway. There’s
currently a navigation restriction during ebb tide that affects all vessels with
a transit draft greater than 33 feet inbound and 36 feet outbound, inhibiting
the free movement of vessel traffic. The
project will not
only improve vessel transit efficiency, but also reduce safety hazards from
this section of the river.
The project is funded in partnership
with JaxPort, the local sponsor, which advanced 100 percent of the construction
cost under an advanced funds agreement.
Part of the Mile Point project infrastructure
includes Helen Cooper Floyd Park, which will remain closed throughout
construction. The park will be used as
an equipment staging area and also contain extensive construction activity throughout
project operations.
Project Details
The Corps of Engineers will construct approximately 4,000
feet of a new west leg training wall; remove approximately 3,300 feet of the
westerly end of the existing training wall to elevation -12 feet mean lower low water (MLLW), which is the average height of
the lowest tide recorded at a tide station each day during the recording period;
construct approximately 2,100 feet of a new east leg training wall; and, dredge
the confluence area to elevation -12 feet MLLW and the flow improvement channel
to elevation -6 feet MLLW, plus one foot allowable over-depth.
The Corps intends to reuse all suitable stone material
recovered from the existing training wall to build the east leg training wall. The
materials will be contained in the Great Marsh Island placement area, helping
restore and create salt marsh. The
project will result in the loss of 8.15 acres of salt marsh at Helen Cooper
Floyd Park, and this will be offset by restoring 18.84 acres of salt marsh at the
nearby Great Marsh Island. In addition, beyond
the mitigation requirement, the Corps will use dredged material from the
project in a beneficial manner to restore up to a total of 53 acres of salt marsh
at Great Marsh Island. This effort will include restoration of high and low
salt marsh as well as low dune and oyster habitat, which is also an excellent
fish environment. The new west leg of
the training wall should also substantially reduce active erosion at Great
Marsh Island.
Other project work includes clearing and grubbing, marine
animal monitoring, bird monitoring, turbidity monitoring, and coordinating with
the U.S Coast Guard to allow its crews to remove and reinstall three
aid-to-navigation structures.
The Corps asks the public to use caution in the area
during staging and construction operations, and for local residents to be
patient with the temporary construction noise as the project progresses. For more information on the Mile Point
Navigation Project, please visit www.saj.usace.army.mil
and go to Ports, Jacksonville Harbor Mile Point.
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Construction
Sequence and Project Map
1. The
contractor's first order of work is to construct the west leg training wall
(WLTW) and wall containment feature
2. Place
geotextile tubes and the temporary containment feature to create an initial
placement area.
3. Dredge
the flow improvement channel and place the material into the initial
containment area.
4. Complete
the remaining portion of the west leg training wall.
5. Place
the remaining geotextile tubes to complete the overall Great Marsh Island
placement area, and remove the temporary containment feature.
6. Complete
the WLTW and begin demolition of the existing training wall along with
excavation and dredging of the main dredging area.
7. The
U.S. Coast Guard will construct two new range towers and demolish and remove
the three existing range tower structures (#7260, #7265, #7287) except for
their foundations.
8. The
contractor will work in all areas of the project that still require
construction.