Evaluation of Sanitary Sewer System Vulnerability: Jefferson Parish, Louisiana

Jefferson Parish is located in southeast Louisiana west of the City of New Orleans. For six months of every year (June through November), southern Louisiana is under threat of tropical storms, hurricanes, and associated storm surges. Most of the urbanized area within the Parish is low-lying with extensive areas of land with elevations at or below mean sea level. This condition has required the construction of levees to protect against flooding from Lake Pontchartrain, the Mississippi River, and the Gulf of Mexico and also makes the area vulnerable to flooding from storms and hurricanes. Hurricane storm surges have the potential of flooding this area with water from the river and the lake, while hurricanes more severe than a fast moving Category 3 have the potential of compromising the flood protection levees in Jefferson Parish. In the wake of Hurricane Katrina's landfall on August 29, 2005, Jefferson Parish suffered significant damage to its infrastructure, particularly the loss of the major components of almost all its public utilities. Although few levees surrounding Jefferson Parish were breached, portions of the Parish were inundated with flood waters as high as eight feet, impacting sewer infrastructure. The Parish and its residents were without the services of basic utilities including water, sewer, and power for two weeks or more. This inoperability of the sanitary sewer pump stations was among the critical issues hindering the Hurricane Katrina recovery effort in Jefferson Parish. This paper describes the preliminary results of the damage analysis phase of the Jefferson Parish Long Term Sewer Mitigation Project (JPLTSMP). The JPLTSMP consists of a conceptual design and cost-benefit analysis for different sanitary sewer pump station flood mitigation alternatives. The study attempts to pin point the weakest areas of the network to flooding as well as offer and evaluate solutions to those weaknesses.