2005 Annual Report 4d.Progress report. This report serves to document research conducted under a Specific Cooperative Agreement between ARS and the School of Geography, University of Nottingham, UK. Additional details of research can be found in the report of the parent project 6408-13000-012-00D, Integrated Analysis of Landscape Processes for Management of Agricultural Watersheds. Installation of field instruments was completed and preliminary results in the Goodwin Creek Experimental Bendway indicate that lateral seepage forces can reach magnitudes great enough to cause mass failure of vertical sections of bank and gully headwalls. Results of this research are critical in modeling soil erosion from bank-side gullies and predicting soil erosion rates from these features.