IPET Risk Maps Released in June for New Orleans Are CORRECT

“The IPET Risk Team performed an exhaustive review over the weekend of the IPET risk analyses and the products generated, and determined that the inundation risk maps released in June are correct,” stated Dr. Ed Link, the IPET director.
The June 2007 IPET risk maps showed a 5.5-foot flood risk reduction for the conditions for the Lakeview (OM2) area and a 4.5-foot reduction for the Hoey’s Basin (OM4) area as of June. The risk maps were released prior to the release of background documentation in an effort to help inform the public as soon as possible. IPET performed a stringent review of the risk maps prior to release.

IPET released the interim draft version of Volume VIII – Engineering and Operational Risk and Reliability Analysis on Nov. 7. This interim draft volume presented the technical aspects used to complete the IPET risk assessment of the New Orleans area. However, a table in one of the Volume VIII appendices cited incorrect elevation data for the two basins, which caused questioning about the accuracy of the previously released risk maps.

The correct elevation data was used in the risk maps released in June.

“IPET apologizes for any confusion or worries the questions about risk map accuracy may have caused residents in the New Orleans area,” Link said.

All IPET findings are peer reviewed by an External Review Panel of national experts from the American Society of Civil Engineers and by the National Academies – National Research Council Committee on New Orleans Hurricane Protection Projects. The IPET interim draft risk volume is being reviewed by these two panels of experts, and their comments and suggestions will be addressed in the final version of the IPET risk volume that will be released sometime in early 2008.

“IPET will continue to review the risk data, and we will inform our partners if any changes or corrections are identified,” Link said. “There will be some small changes made to new risk maps in the future, but these will be small adjustments and not large shifts. These minor adjustments will address wave runup, the impact of pumping, and the interflow among adjacent sub-basins.

“Again, these will be very minor adjustments as modeling advances are made and implemented to the risk process.”

The interim draft version of IPET Volume VIII contains the technical documentation of the IPET risk process that was applied to assess the hurricane protection system in southeast Louisiana. The IPET risk results using this process were initially released in map form on June 20 for pre-Katrina and current conditions as of June 2007.

Similar risk information products were generated for the planned 100-year Hurricane Protection System and released on Aug. 22 by the Corps of Engineers’ New Orleans District. This information was generated using the same risk process outlined in the interim draft Volume VIII and are correct as well.

IPET was established by the commander of the U.S. Army Corps of Engineers and comprised more than 150 nationally recognized experts from more than 50 different organizations (eight federal, state and local government agencies; 25 universities and 23 private sector firms).

IPET was specifically tasked with gathering and analyzing data to answer five basic questions:
The System (what was the status of the protection system on August 29, 2005),
The Storm (what exact forces did Katrina put on the system),
The Performance (how did the system respond),
The Consequences (understanding the flooding and the losses – both economic and loss of life), and
The Risk (what is the risk and reliability of the protection system).

More than 4,300 documents, including IPET reports, data, and research information are available on the public Web site, https://IPET.wes.army.mil.