River Bathymetry Toolkit is available for free and is under active development. A plugin for ArcGIS Desktop 10 and ArcGIS Spatial Analyst, RBT provides tools for cutting cross sections and longitudinal profiles into high resolution DEMs to extract hydrologic parameters such as wetted area, bankfull width, hydraulic radius, gradient and sinuosity. On-going developments include utilization of the detrended raster to investigate flooding outside a main channel at any prescribed discharge or flow stage.