Reconnaissance Level Study Mississippi Storm Surge Barrier

Abstract

This paper reports a reconnaissance level study of a storm surge barrier in the Mississippi River. Historical hurricanes have shown storm surge of several meters along the Mississippi River levees up to and upstream of New Orleans. Future changes due to sea level rise and subsidence will further increase the risk of flooding due to hurricane storm surge. A surge barrier downstream of New Orleans has been considered as an alternative to levee raise along the Mississippi River. Hydraulic computations show that the build-up of water behind the barrier due to the Mississippi River flow is (much) lower than the hurricane surge protruding up the river in the no-barrier situation. The barrier will probably eliminate the need to upgrade the system upstream of the barrier while providing the same level of hurricane risk reduction. A hybrid barrier (a combination of different gate types) with a primary swing gate for navigation (and flow) and secondary lift gates to accommodate for flow is a technically feasible alternative. The barrier remains open for almost the entire year and would only to be closed during severe tropical events (say once every 2 -3 years). Several measures are included in the conceptual design to mitigate the navigation impact. The construction costs of the barrier are estimated at $1.6 -2.6 billion. It is recommended to compare the investment costs of a barrier including adjacent tie-ins to the existing HSDRRS to the costs of upgrading and maintaining the levee system throughout the city of New Orleans.

Assessing the Multiple Impacts of Extreme Hurricanes in Southern New England, USA

“…For the three-barrier system protecting Venice, Italy, another study focused on determining the effect of various operation strategies (e.g., closure of only two barriers) on water levels in Venice Lagoon [3]. Storm surge modeling was also utilized in assessing the potential performance of proposed storm surge barriers in a Danish fjord [4] and at the mouth of the Mississippi River in the southern US [5]. Finally, several studies used a modeling approach to retrospectively evaluate the effects of barrier islands on storm surge elevation and water quality in the shallow back bays behind the barrier islands [6,7].…”

Storm Surge Barrier: Overview and Design Considerations

“…A barge gate may be buoyant or equipped with gated openings to reduce hinge and operating forces (van Ledden et al, 2012). A barge gate can also be called a swing gate.…”

“…As no detailed information of the design is available at this stage, these formulas are based on the main cost elements for a storm surge barrier. Several of these methods have been proposed (Jonkman et al, 2013;van Ledden et al, 2012;de Ridder) but the accuracy of these methods is unknown. Subsequently it is not known which of these methods is the most reliable.…”

“…In such regions preserving ecology or maintaining navigation have a large value and the high costs of storm surge barriers compared to the alternative type of barriers can be afforded. For example, storm surge barriers are currently proposed at Houston, USA (De Vries, 2014); New Orleans, Mississippi, USA (van Ledden et al, 2012), New York, USA (TU Delft, 2013;Dircke et al, 2009;Aerts et al, 2013); Manila, Philippines; Ho Chi Minh City, Vietnam and Tokyo, Japan (Ruiz Fuentes, 2014).…”

“…In such regions preserving ecology or maintaining navigation have a large value and the high costs of storm surge barriers compared to the alternative type of barriers can be afforded. For example, storm surge barriers are currently proposed at Houston, USA (De Vries, 2014); New Orleans, Mississippi, USA (van Ledden et al, 2012), New York, USA (TU Delft, 2013;Dircke et al, 2009;Aerts et al, 2013); Manila, Philippines; Ho Chi Minh City, Vietnam and Tokyo, Japan (Ruiz Fuentes, 2014).Currently only fifteen storm surge barriers worldwide have been designed and constructed so far. These structures show a great variety in design and appearance as many different hydraulic gate types are applied, likely due to the unique conditions and requirements they are facing.…”