The scour development in floods at abutments (Gjunsburgs & Neilands 2001, 2004, 2005, Gjunsburgs et al. 2004, 2005, 2006) and at elliptical guide banks is studied. The scour hole extents at abutments and guide banks are different. At the upstream head of the elliptical guide banks, a streamline concentration, a local increase in velocity, and the development of a scour hole were observed. The differential equation of equilibrium for the bed sediment movement under clear-water conditions is used, and a method for computing the scour development in floods at elliptical guide banks is elaborated. The method is confirmed by experimental data. The “ERoBo” computer program is elaborated and used in calculations. The scour hole pa-rameters – depth, width, and volume – can be calculated by this method after one, two, or several floods both at the stage of designing the bridge crossings or in the maintenance period.