Detailed view for Inner Harbor Navigation Canal Lake Borgne Surge Barrier (IHNC)

Hurricane and Storm Damage Risk
USA, New Orleans, Louisiana,
Short description

2,400 meter-long , 8 meter- high barrier wall, sector gate (46 m), barge gate (46 m), lift gate (17 m), and a complete flood-wall closure-storage of 6.4 million cubic meters of water from overtopping
- 100-year-level risk reduction
- 500 year design for resilience

Progress status
In operation since May 24th, 2011
Cost estimation
$1.1 Billion

US Army Corps of Engineers

Prime contractor

INCA*/Gerwick JV
*INCA bought by Tetra Tech in 2008

Consortium work

Shaw Environmental & Infrastructure* *bought by CB&I in 2012



PIANC References for this project
  • PIANC , INCOM WG 26, 2006 : Design of Movable Weirs and Storm Surge Barriers
  • Philippe Rigo (BE), Dale Miller (USA), R Daniel (NL), ...
  • Referenced and presented during Smart Rivers Conference in 2012 New Orleans, LA, USA

The Inner Harbor Navigation Canal (IHNC) and lock structure were placed into operation in May 1923. The canal and lock were built to provide navigation between the Mississippi River and Lake Ponchartrain. The lock is located at Mississippi River Mile 92.6 above Head of Passes (AHP), northeast of downtown New Orleans. It isa reinforced concrete, closely-spaced, wood pile-founded “U” frame structure having a chamber width of 75 feet and length of 640 feet. The lock has a depth of water over the sill of 31.5 feet at Mean Low Gulf (MLG).

The IHNC Replacement Lock will be located about one-half mile north of the existing lock. The new lock will be a 110-foot wide barge and ship lock having a usable length of 1,200 feet, and providing 36 feet of draft. The new lock will be pile supported and use an innovative U-frame, float-in, reinforced concrete shell for construction. The new lock will also use sector gates to provide lockage with normal flows and flood protection from hurricane storm surges in the reverse direction.

The land along the canal has been heavily developed over the years and is now entirely devoted to industrial/port use. This development and the close proximity of historic and residential structures on the canal banks, places severe space restrictions on the site. Traditional construction techniques cannot be used; therefore, the new lock will be the first in the world constructed via float-in technology.

Documents to download
  • 11-06 - IHNC Project (USA).pdf - 11-06 - IHNC Project (USA).pdf