The cost effectiveness of compartmentation of the Orleans Metro Bowl

The cost effectiveness of compartmentation of the Orleans Metro Bowl

Aalberts, M.L.

Stelling, G.S. (mentor)
Kok, M. (mentor)
Jonkman, S.N. (mentor)
Vrijling, J.K. (mentor)

Civil Engineering and Geosciences

2008-06-13

After Hurricane Katrina the Bring New Orleans Back committee advised to use the Gentilly Ridge to split the Orleans Metro Bowl into compartments in order to reduce the consequences of a flood. The Gentilly Ridge is a natural sand elevation (ridge) of approximately 0,50 1,00 meter NAVD88 in the OMB landscape. The objective of this thesis is to determine the cost-effectiveness (risk reduction versus construction costs) of compartmentation of the Orleans Metro Bowl (OMB) in comparison with an improvement of the primary levee system. Three alternative compartment levees are compared with one primary system improvement. In this thesis the total flood risk of the OMB has been represented in two scenarios: the Katrina event (hurricane class III) and a hurricane class IV event. - The Katrina event is the complete scenario of the Katrina disaster of August 29, 2005. The probability of the event is set to be 1/50 per year. - A hurricane category IV event. The probability of the event is set to be 1/200 per year. Once the probability (in probability/year) and the consequences (in $) of a scenario and alternative have been determined the risk (in $/year) is known. This risk is calculated to a Net Present Value ($) to compare with the costs of a alternative ($). With a detailed cross-section of the compartment levees a calculation of the heightening costs of an earthen levee for each compartment trace has been made. Compartment levee 3 appeared to be less cost-effective than the levee improvement and drop-out. An boundary optimal design level for compartment levee 1 and 2 is calculated and appeared to be both 1,50 meter NAVD88. To overcome a disaster like Katrina, a compartment levee alone will not suffice, therefore the cost effectiveness of a combination Levee improvement and compartment levee is elaborated. Compartment levee 1 (1,50 meter NAVD88) is a quick and cost effective way to deduct the total risk for economical damage in the OMB for the short term. Once the total primary system has been improved, a compartment levee (trace 1) is still of economical value.

compartmentation
katrina
new orleans
cost-effectiveness
levee

http://resolver.tudelft.nl/uuid:ef885a70-970a-4ff1-ab9b-ff3213880255

TU Delft, Civil Engineering and Geosciences, Hydraulic Engineering

Student theses

master thesis

(c) 2008 M.L. Aalberts