Dam and levee systems are crucial to the management of our nation's water resources. The United States has 2.3 trillion dollars in property value, 23.7 million people, and 6.87 million buildings protected by these structures. Currently, the United States Army Corps of Engineers has 740 dams and 12,500 miles of levee systems in its portfolio. These structures are vulnerable to erosion with surface erosion accounting for over 50 percent of earthen embankment failures. Due to recent changes in our climate, overtopping of levees and dams leading to surface erosion has presented additional concern for the safety of these structures. Traditional stabilizers including cement and lime have been shown to help resist erosion during overtopping, but the need for a more environmentally friendly, renewable stabilizer has become evident. This study evaluates the effectiveness of naturally sourced polymers (biopolymers) in improving vegetation growth to create higher erosion resistance in existing earthen embankments. The first biopolymer, xanthan gum, is a biopolymer that is regularly used in the food industry and is readily available. The second is an extracellular polymeric substance (EPS) polymer created using the bacteria Rhizobium Tropici. Laboratory jet erosion tests are performed on both untreated and biopolymer-treated samples with bare earth and vegetated conditions. To identify transferability to field applications, in situ jet tests are conducted on a field site treated with EPS to determine the changes to erosion resistance of material treated with these eco-friendly stabilizers during an overtopping event. The results show that Rhizobium and Xanthan treatments improve the erosion resistance in a bare earth condition, being useful in post construction conditions. Field results show that Rhizobium improves the root mass and vegetation, therefore improving the erosion resistance.
