Courtesy of NASA
Hurricane Isaac at mid day, Aug. 29, hangs on southern Louisiana below New Orleans


A mid-day situation report from the U.S. Army Corps of Engineers Mississippi Valley Division indicates all "major" structures flood control structures in the Greater New Orleans Hurricane and Storm Damage Risk Reduction System are closed, including the West Closure Complex.

The WCC is designed to reduce surge risk in a large area of the West Bank by removing more than 25 miles of levees, floodwalls, a floodgate, and pumping stations along the Harvey and Algiers canals from direct exposure to storm surge.

There are 35 small valve openings controlled by Southeast Louisiana Flood Protection Authority-West that are still being held open to allow gravity flow, although about half are expected to be closed soon.

All of the city's outfall canal pumps are functioning properly, with some minor "hiccups" that have been mostly resolved.

In Plaquemines Parish there is over-topping of a non-federal levee on the East Bank, and a predicted high storm surge on the West Bank this afternoon could result in over-topping of the non-federal levee on that side as well.

[Local radio reports that Jefferson Parish has ordered mandatory evacuation along highway 23 from the Oakville Floodgate south to Venice.]

USACE levees are not predicted to be threatened with overtopping. The Corps is providing technical analysis in the form of hydrograph modeling for the Plaquemines Parish area, and has just given contingent approval to reverse the flow of the Caernarvon fresh water diversion channel to help unwater the East bank area that has been flooded by storm surge.

Corps resources are flowing toward southern Louisiana, including 105 generators on the ground in Baton Rouge that are available now or are being readied for deployment. Some Louisiana parishes are requesting pumps and the Corps is working to match available equipment with needs, although the Federal Emergency Management Agency has not yet requested pumps.

No major issues are reported from Mississippi at mid-day Wednesday.