Predicting stream bank erosion on the Northern Gulf of Mexico coastal plain: Pitfalls and solutions

According to the EPA's 2000 National Water Quality Inventory (USEPA 2000), sediment pollution is the second leading cause of impairment to U.S. streams. In areas where sediment pollution and eroding stream banks coincide, professionals are apt to cite bank erosion as a suspected source of contamination. Bank erosion can lead to a number of problems, not only by contributing sediment, but by altering channel dimensions as bank area is lost. Thus, funds allotted to federal, state and county agencies for soil conservation and stream stabilization are often used to implement techniques aimed at curbing lateral erosion. Realistically, it is impossible to secure funding for complete restoration of all eroding channels. What is needed is a predictive field-based method for determining sites that will incur the most rapid erosion and approximately how much sediment will be contributed to the channel. With such a powerful tool for prioritizing restoration sites, more funding could be funneled to high risk sites, resulting in more comprehensive restoration projects. In the last 10 years, several studies have been conducted correlating observed rates of bank erosion with field-measured erosion potential factors (Harmel et al. 1999; Rosgen 2001; Jennings and Harman 2001; Van Eps et al. 2004; Sass and Keane 2012). Such studies, when carried out in a single hydrophysiograhic region and on hydrologically and morphologically similar streams, can provide professionals a means for rapidly estimating the sediment contribution of eroding banks in that region. Our study is developing regional bank erosion curves for the Northeast Gulf Coastal Plain thereby providing local management experts a valuable tool for the speedy prioritization of enhancement and restoration projects and follow-up monitoring of restoration efforts. Our study applies an established method (Rosgen 2001; USEPA 2012) but seeks to improve on some of the weaknesses inherent to the method.Conference Pape