1
Closing the
Mississippi River Gulf Outlet (MRGO)
Environmental and Economic Implications
Coastal Wetland Planning, Preservation, and
Restoration Act (CWPPRA) Outreach Committee Topic
Series December 2001
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Case Study of the MRGO

• Project background

• Impacts to the region

• Calls for action

• What does closing mean?

• Future considerations

3
MRGO - Background Info

• 1956 Approved by Congress

• 1958-65 Construction 92 Million

• Authorized dimensions
• 650 surface width, 500 bottom width
• 36 depth
• 76 miles

• 311 million yd3 of dredged volume

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MRGO Location
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MRGO Rationale

• Navigation shortcut
• Economic development

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... the (MRGO) is a chance for the industrial
development of St. Bernard parish as a supplement
to the great industrial growth of neighboring
Orleans parish New Orleans States News, 1957
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...Excavation of the (MRGO) could result in
major ecological change with widespread and
severe ecological consequences US Dept. of
Interior, 1958
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... This department is greatly concerned about
the direct (MRGO) influence on fish and wildlife
resources...we anticipate considerable indirect
losses due to changes in currents, saltwater
intrusion, drifting of spoil into adjacent areas,
and other project associated factors Louisiana
Wildlife and Fisheries Commission, 1958
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MRGO - Environmental Impacts

• Land loss from excavation

• Dredge disposal

• Accelerated erosion

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Saltwater Intrusion
1959-1961 12 ppt 1962-1964 12
ppt (US Dept. of Interior 1979)
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MRGO Habitat Loss Transition (USACE 1999)

• Lost, destroyed, or severely altered
  
• 1500 acres cypress swamps and levee forest
• 3400 acres fresh/intermediate marsh
• 10300 acres brackish marsh
• 4200 acres saline marsh

• Habitat transition
  
• 11000 acres fresh/intermediate to brackish
• 19000 acres brackish to saline

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Habitat Loss and Displacement
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Waterfowl
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Fur Industry
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Fisheries Reduction and Displacement
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Fisheries Displacement
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Storm-Surge Superhighway?
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MRGO - Economic Impacts

• Initial surge regional employment

• 28/acre to impacted landowners

• Local employment 5000-15000 jobs

• Regional barge traffic - limited export

• 3 of shipping in Southeast La

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MRGO Maintenance Cost

• 22.1 Million per year for dredging

• 41.7 Million in 1998 after Hurricane Georges

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MRGO Maintenance Cost

• 1998 4.8 deep draft (gt20) vessels per day

• 12,657 per deep draft vessel, per day

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Environmental costs?

• 20,000 acres lost

• Ecosystem service values 300 - 4300/acre

• 250 million to - 2 billion over past 40 years

• Estimating environmental cost
• initial value?
• discount rates?
• shape of loss function?

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Calls for Action

• 1960s-1970s USFWS, LDWF

• 1980s-1990s Environmental groups

• 1998 Formal recognition under Coast 2050

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Calls for Action
This council does hereby request Louisianas
Southeast Congressional Delegation establish a
task force to develop a process that will result
in the timely closure of the MRGO St. Bernard
Parish Council Resolution December 1998
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What does it mean to close the MRGO?

• Closing ?? Closing

• Series of mitigation and restoration proposals

• Halting of dredging

• Channel maintenance for fishermen boaters

• Close channel to vessels gt 12 draft

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Closing the MRGO
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Closing the MRGO
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Closing the MRGO
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MRGO Restoration
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A Diversion for MRGO?
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What has been done?

• Speed reductions proposed

• Rock-buttressed dredge spoil

• Major funding needed to finance projects

• Formation of MRGO Policy Committee

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Future Considerations
To revitalize the process for a plan to modify
the MRGO, the key is to expedite the
Re-evaluation study MRGO Policy
Committee Status Report 2000
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Future Considerations

• USACE Re-evaluation Study of MRGO
• Hinges economic feasibility for navigation

• Consensus for downsizing the MRGO
• Address displacement of navigation
• Port of New Orleans expansion
• Millenium Port

• How long?

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A Similar Effort? The
Cross Florida Barge Canal

• Goal Connect Atlantic to Gulf via 107 miles of
  channel

• 1971 Nixon halts construction - calls for
  re-evaluation

• 1986 Congress deauthorizes project

• 1990 Project lands revert back to Florida

• 2001 Restoration/mitigation debate ongoing

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Summary and Conclusions

• The MRGO has accelerated the rate of coastal
  degradation in St. Bernard

• Estimated 20,000 acres lost and 20,000
  transitioned toward higher salinity

• Displacement and reductions of fisheries and
  wildlife

• Economic growth less than expected

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Summary and Conclusions

• High maintenance, environmental costs

• Consensus for closure exists

• Closing ?? Closing

• Beyond the conceptual stage
• Formation of MRGO policy committee
• Corps Re-evaluation study
• Negotiations with shipping industry

• More realistic time horizons needed

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Acknowledgements