Coastal & Port Engineering Considerations

sixcageyΜηχανική

22 Φεβ 2014 (πριν από 3 χρόνια και 3 μήνες)

60 εμφανίσεις

Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Kevin Bodge, Ph.D., P.E.

Port & Coastal Engineer

Senior Vice President
--

Olsen Associates, Inc.

Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Physical Impacts


1.
River hydraulics (flow, levels & sedimentation)


Deeper, hydraulically
-
efficient artificial channel



--

increases upstream salinity



--

increases water levels



--

changes flow patterns



Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Physical Impacts


1.
River hydraulics (flow, levels & sedimentation)


Deeper, hydraulically
-
efficient artificial channel



--

increases upstream salinity



--

increases water levels



--

changes flow patterns


2.
Storm water levels


--

Tide ranges increase up to 0.4 feet


--

Storm tides not described



Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Physical Impacts


1.
River hydraulics (flow, levels & sedimentation)


Deeper, hydraulically
-
efficient artificial channel



--

increases upstream salinity



--

increases water levels



--

changes flow patterns


2.
Storm water levels


--

Tide ranges increase up to 0.4 feet


--

Storm tides not described


3.
Salt water intrusion


--

impacts to aquifer . . . not included


Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

SOME OF THE STUDIES NOT IN THE DRAFT REPORT FOR PUBLIC REVIEW & COMMENTS

Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Physical
Impacts, Cont’d

4. Salinity


--

The Corps claims that natural changes in salinity cause more


stress than the project’s changes.


--

The impacts are real, but not clearly presented


--

Fish & shrimp studies etc. are still ongoing




NO ACTION (No Project)

50
-
Ft PROJECT

Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Physical Impacts, Cont’d



5.
Ship Wake and Bank Erosion


--

Corps study claims no increase in ship wake, but that is based




upon the current design vessel.


--

Deeper channel


Bigger Ships


Greater Ship Waves





970’ ship length at 15 knots: wake = 3.7’

1260’ ship length at 15 knots: wake = 6.8’ (84% increase)


970’ ship length at 10 knots: wake = 0.4’

1260’ ship length at 10 knots: wake = 1.0’ (150% increase)

Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Physical Impacts, Cont’d



6.

Offshore Disposal Area


--

Construction requires disposal of 18 million


cubic yards (
mcy
)


--

Existing offshore disposal area capacity =



3.3
mcy


--

Expanded offshore disposal area close to



sand borrow areas.




Coastal & Port Engineering Considerations

of the Jacksonville Harbor Deepening Study

Fiscal
Impacts


1.
Initial Construction Cost


Fed: $350M (48%) Local: $384M (52%)


2.
Maintenance Dredging Costs


--

Fiscal projections are not included in report


--

Local cost
-
share increases from 0% to 50% !



Dredging requirements will increase by 130,000+ cy/
yr



or, about $1.2M per year.


Probable annual dredging
req’t

= 1,540,000 cy/
yr


Probable equivalent total cost = $14 million / year


Probable NON
-
FEDERAL cost = $7 million/year.

My estimates,
not in report