Gennaro Bifulco Stephanie Camilo Rickie Caudill Sam Henry Diane - PowerPoint PPT Presentation

Gennaro Bifulco Stephanie Camilo Rickie Caudill Sam Henry Diane Wurst

What is a Levee?  An embankment to prevent the overflow of a river  Analogy  Dams are for lakes  Levees are for Rivers

History  Levees first built in New Orleans in the late 1800 ’s  Built up and down the Mississippi River, as well as along the Gulf of Mexico and Lake Ponchartrain  New Orleans was utilizing 350 miles of levees  Government decided the levees had to be able to handle a Category 3 Hurricane

Causes of Failure  Settling was not considered in Hurricane Design for the canal and weren’t considered until 50 years thereafter  Design for Category 3 Hurricane  Pre existing Depression  19-25mm Layer of organic silty clay  Pumping of Groundwater Caused Drying of Swamp/Marsh Layer  Lack of funding for maintenance

Geology of the 17 th Street Canal Levee Layers of soil product of:  Nearby Lakes & Rivers: Lake Pontchartrain & Maurepas, and Mississippi River  Marsh/Swamp Deposits=High Organics & Very Low Strength

Aftermath of Levee Failure

Solutions  Levees are now being:  The New Orleans Levee Project won't be finished  Reinforcement until June 1 , 2011 , at the  Raised earliest.  Stability improved  Seepage control

Conclusions  The failure at 17 th Street was due to various geological conditions:  Dried out organic swamp soils with low strength  Sensitive clay layer getting exposed to water during Hurricane Katrina  With more studies of geotechnical engineering then New Orleans can be improved to be more hurricane resistant

Questions?

References  http://www.cnn.com/2005/WEATHER/08/28/hurricane.katrina/  http://news.nationalgeographic.com/news/2005/09/0902_050902_katrina_levees.html  Tibbetts, J. (2006, January). Louisiana’s Wetlands: A Lesson in Nature Appreciation. Environmental Health Perspectives, 114(1). Retrieved January 24, 2010, from EBSCOhost database.  Seed, R.B., Bea, R. G., et al. (2008, May). “New Orleans and Hurricane Katrina: The 17 th Street Drainage Canal.” Journal of Geotechnical and Geoenvironmental Engineering. Retrieved January 24, 2010.