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“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. Case Study of the MRGO. Project background. Impacts to the region.
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“Closing” theMississippi River Gulf Outlet (MRGO): Environmental and Economic Implications Coastal Wetland Planning, Preservation, and Restoration Act (CWPPRA) Outreach Committee Topic Series December 2001
Case Study of the MRGO • Project background • Impacts to the region • Calls for action • What does “closing” mean? • Future considerations
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
MRGO Rationale • Navigation shortcut • Economic development
“... 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
“...Excavation of the (MRGO) could result in major ecological change with widespread and severe ecological consequences” US Dept. of Interior, 1958
“... 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
MRGO - Environmental Impacts • Land loss from excavation • Dredge disposal • Accelerated erosion
Saltwater Intrusion 1959-1961: 12 ppt 1962-1964: 12 ppt (US Dept. of Interior 1979)
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
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
MRGO Maintenance Cost • $22.1 Million per year for dredging • $41.7 Million in 1998 after Hurricane Georges
MRGO Maintenance Cost • 1998: 4.8 deep draft (>=20’) vessels per day • $12,657 per deep draft vessel, per day
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?
Calls for Action • 1960s-1970s: USFWS, LDWF • 1980s-1990s : Environmental groups • 1998 Formal recognition under Coast 2050
Calls for Action “…This council does hereby request Louisiana’s 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
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 > 12’ draft
What has been done? • Speed reductions proposed • Rock-buttressed dredge spoil • Major funding needed to finance projects • Formation of MRGO Policy Committee
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
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?
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
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
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