Thousands of miles of levees exist in the United States and around the world and failure of these levees as a result of breaching has the potential to cause severe flooding damage. A technology, the PLUG, has been developed to temporarily reduce the flow through a levee breach as an alternative to traditional methods. This study is focused on developing initial guidance on the parameters for sizing a PLUG using a 1:100 (model:prototype) Froude scaled model. It was found that for the PLUG to effectively reduce flow through the breach, the required ratio of the PLUG length to the breach width is greater than two (L/W > 2), and that effectiveness increases as the ratio between the PLUG diameter and water depth (D/d) increases. Effectiveness also increases when the percent fill (P) is between 65 – 75 percent. Trends in the threshold between catastrophic failure and success were also noted.

Levee breaching is the most frequent and dangerous form of levee failure. A levee breach occurs when floodwater breaks through part of the levee creating an opening for water to flood the protected area. According to National Committee on Levee Safety (NCLS), a reasonable upper limit for damage resulting from levee breaching is around $10 billion per year during 1998 and 2007. This number excludes hurricanes Katrina and Rita in 2005 which resulted in economic damages estimated to be more than $200 billion dollar and a loss of more than 1800 lives. In response to these catastrophic failures, the U.S. Army Corps of Engineers (USACE) started to develop the National Levee Database (NLD) on May 2006. The NLD has a critical role in evaluating the safety of the national levee system. It contains information regarding the attributes of the national levee system. The Levee Analyst Data Model was developed by Dr Norm Jones, Jeff Handy and Thomas Griffiths to supplement the NLD. Levee Analyst is a data model and suite of tools for managing levee information in ArcGIS and exporting the information to Google Earth for enhanced visualization. The current Levee Analyst has a concise and expandable structure for managing, archiving and analyzing large amounts of levee seepage and slope stability data. (Thomas 2009). The new set of tools developed in this research extends the ability of the Levee Analyst Data Model to analyze and mange levee breach simulations and store them in the NLD geodatabase. The capabilities and compatibilities with the NLD of the new geoprocessing tools are demonstrated in the case study. The feasibility of using GSSHA model to simulate flooding is also demonstrated in this research.

The devastating levee failures associated with hurricanes Katrina and Rita, and the more recent Midwest flooding, placed a spotlight on the importance of levees and our dependence on them to protect life and property. In response to levee failures associated with the hurricanes, Congress passed the Water Resources Development Act of 2007 which established a National Committee on Levee Safety. The committee was charged with developing recommendations for a National Levee Safety Program. The Secretary of the Army was charged with the establishment and maintenance of a National Levee Database. The National Levee Database is a critical tool in assessing and improving the safety of the nation's levees. However, the NLD data model, established in 2007, lacked a structure to store seepage and slope stability analyses – vital information for assessing the safety of a levee. In response, the Levee Analyst was developed in 2008 by Dr. Norm Jones and Jeffrey Handy. The Levee Analysis Data Model was designed to provide a central location, compatible with the National Levee Database, for storing large amounts of levee seepage and slope stability analytical data. The original Levee Analyst geoprocessing tools were created to assist users in populating, managing, and analyzing Levee Analyst geodatabase data. In an effort to enhance the Levee Analyst and provide greater accessibility to levee data, this research expanded the Levee Analyst to include modifications to the data model and additional geoprocessing tools that archive GeoStudio SEEP/W and SLOPE/W simulations as well as export the entire Levee Analyst database to Google Earth. Case studies were performed to demonstrate the new geoprocessing tools' capabilities and the compatibility between the National Levee Database and the Levee Analyst database. A number of levee breaches were simulated to prototype the enhancement of the Levee Analyst to include additional feature classes, tables, and geoprocessing tools. This enhancement would allow Levee Analyst to manage, edit, and export two-dimensional levee breach scenarios.