For more information about GIS and Hydrology, see http://www.ce.utexas.edu/prof/maidment To obtain CRWR-PrePro to link ArcView with HEC-HMS, see http://www.ce.utexas.edu/prof/olivera/prepro/prepro.htm To take an online spatial hydrology course, see http://campus.esri.com/campus/home/home.cfm