NOLA’S LAST LINE OF DEFENSE: THE LAKE BORGNE SURGE BARRIER

LBSB_Map_Courtesty of enr construction
[MAP OF LAKE BORGNE SURGE BARRIER PROTECTIONS WITH NEW ORLEANS EAST AND ST. BERNARD RISK REDUCTION SYSTEMS. IMAGE COURTESY OF ENGINEERING NEWS RECORD]

The images that follow document a visit to arguably the most critical piece of American infrastructure built in the last decade, the Inner Harbor Navigation Canal Lake Borgne Surge Barrier.  Straddling Bayou Bienvenue from the Gulf Intracoastal Waterway (GIWW) to the abortive Mississippi River-Gulf Outlet canal or MRGO (“Mister Go”), the surge barrier represents a strange kind of monstrous mea culpa from the Army Corps writ in infrastructure.  While civil courts have found the Corps work in constructing MRGO did not contribute to interior flooding, independent hydraulic analysis has shown that the eroding banks of the disused canal created a wide superhighway for flood waters to access into the interior of New Orleans.  Some allege that the four levee failures and considerable loss of life along the Industrial Canal–into which MRGO feeds–were directly attributable to the so-called “MRGO Funnel.”

Despite the Army Corps’ formal deflection of responsibility in court, MRGO has drawn quite a bit of the Corps attention after Katrina.  In 2007, they announced that MRGO would be closed to through traffic and blocked by an earthen dam.  Still other environmental advocacy groups want the entire Outlet restored to wetland habitat.  Since its construction in the 1960s, MRGO’s width has nearly tripled.  As vital wetland habitat is eroded, New Orleans loses a key element of its natural hurricane protection.  The dilating Outlet is also introducing greater quantities of salt to intrude into marshland, further depleting delicate marsh ecosystems.

Arguably, no American city’s fortune is bound tighter to a piece of infrastructure as New Orleans is to the Surge Barrier.  The largest design built project in the Army Corps history was lightly tested for first time as Isaac descended on the Crescent City.  With NOAA forecasting an active hurricane season, the Corps won’t have to wait long for a a more rigorous trial.

Bayou Bienvenue Lift Gate Control StructureGIWW Sector Gate Control Structureconcrete top of New Orleans East Risk Reduction SystemN. Access Gatelooking west on levee top towards Michoud Canallooking east on levee top along gulf intracoastal waterway
Sector gate openconcrete pilings of main wall with Bienvenue Liftgate insector gatesector gate 2sailboat passing through sector gatetowards michoud canal
critical habitat warningbarge gate openingconstruction barge passagebarge passage 1barge passage 2

LAKE BORGNE SURGE BARRIER , a set on Flickr.

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