FOOTNOTE ON ADDITIONAL RISKS ... CLICK HERE
First, a little bit of background:
Hurricane Katrina was the costliest and one of the five deadliest hurricanes in the history of the United States.
It was the sixth-strongest Atlantic hurricane ever recorded and the third-strongest hurricane on record that made landfall in the United States.
Katrina formed on August 23 during the 2005 Atlantic hurricane season and caused devastation along much of the north-central Gulf Coast.
The most severe loss of life and property damage occurred in New Orleans, Louisiana, which flooded as the levee system catastrophically failed, in many cases hours after the storm had moved inland.
In Louisiana, the federal flood protection system in New Orleans failed in more than fifty places.
[Photo source: http://www.freerepublic.com/focus/f-news/1517817/posts ]
[Above: From the 17th Street Canal breach, a layer of weak or weakened subsoil succumbed to lateral loads imposed by elevated water levels fed into the canal by storm surge on Lake Pontchartrain's southern shore, allowing the entire cross section of the embankment and capwall to be displaced an estimated 42 feet from their pre-storm position. Below: Planned repairs of a levee by Corps of Engineers.]
Nearly every levee in metro New Orleans breached as Hurricane Katrina passed east of the city, subsequently flooding 80% of the city and many areas of neighboring parishes for weeks.
At least 1,836 people lost their lives in Hurricane Katrina and in the subsequent floods, making it the deadliest U.S. hurricane since the 1928 Okeechobee Hurricane. The storm is estimated to have been responsible for $81.2 billion (2005 U.S. dollars) in damage, making it the costliest natural disaster in U.S. history.
The catastrophic failure of the flood protection in New Orleans prompted immediate review of the Army Corps of Engineers, which has, by congressional mandate, sole responsibility for design and construction of the flood protection and levee systems. There was also widespread criticism of the federal, state and local governments' reaction to the storm, which resulted in an investigation by the U.S. Congress, and the resignation of Federal Emergency Management Agency director Michael D. Brown. Conversely, the National Hurricane Center and National Weather Service were widely commended for accurate forecasts and abundant lead time.
NOW FOR THE IMPORTANCE OF COMMUNICATION AND INFORMATION FLOW IN RISK MANAGEMENT!
ASCE urges corps to tell residents of continuing flooding risk
High water, construction could prove dangerous to levee stability
With the Mississippi River again creeping up its banks, authorities are scrambling to stop nearby construction and demolition because the work could undermine levees during this vulnerable period of high water.
Pile driving, excavation and other dirt-moving procedures are never allowed within 1,500 feet of a river levee unless the Army Corps of Engineers determines it's no threat to levee stability. Even then it must be permitted by the appropriate levee district, officials said. [1 foot = 0.305m]
But enforcement of these restrictions is more critical than ever when the river is high and levee damage could result, said Fran Campbell, executive director of the East Jefferson Levee District.
"It's all about not creating a path for the water to come through a levee," she said.
"I think most people assume the river levees can't fail, just like they didn't think that the hurricane protection levees could fail. But these rules are serious. They're in place for a reason."
The river stood at 16-1/2 feet at the Carrollton gauge in New Orleans on Monday, down from almost 17 feet on Thursday, the day before the Army Corps of Engineers opened the Bonnet Carre Spillway to divert some of the surge to Lake Pontchartrain. But the National Weather Service predicts it will climb back to 17 feet by Thursday and will stay there through April 22.
Campbell said levee district police officers and inspectors are checking multiple work sites daily and have shut down about a dozen of them. They have halted home building, swimming pool construction, a house raising, apartment renovations, fence removal and other activities.
Police also are driving side streets within the 1,500-foot zone grid in search of violators.
Some of the halted activities have permits that the levee district issued before the Mississippi River hit an elevation of 11 feet at the Carrollton gauge last month, the point at which invasive work must stop. But a permit still doesn't allow work during periods of high water, Campbell said. The paperwork simply makes it more efficient for authorities to visit each site to ensure work has stopped.
"We're also seeing a rash of people right now who're doing work without levee district permits, and that makes stopping it more difficult," she said.
Orleans Levee District Executive Director Stevan Spencer said he doesn't see as many violations because there are few residential structures along the river in New Orleans and the Port of New Orleans helps watch for business activities in the area.
But Spencer said the levee district has stopped work on two sites this week where piles were being driven, in one case only 700 feet from the levee. Neither violator had a permit, he said.
Spencer and Campbell said they are again appealing to the governments of New Orleans and Jefferson Parish not to issue building permits until applicants have levee permits in hand.
Campbell and Spencer said they've not cited any violators.
"We're trying to be nice and help people understand what's at stake here," Campbell said. "And we know people lose money when they have to stop work. That's another reason why we all need to be on the same page."
TOP Sheila Grissett can be reached at firstname.lastname@example.org