This NSF-REU site on Interdisciplinary Water Sciences and Engineering at Virginia Tech was established in 2007. We have successfully completed three cycles (2007-09), (2011-13) and (2014 - 2016) of this site. Currently, implementation of the fourth cycle is in progress with an international component. As of summer 2019, we have graduated 115 excellent undergraduate researchers (78 women + 37 men) (REU fellows) representing 60+ different institutions located across the United States and Canada. Faculty members and their graduate students from a variety of disciplines including Civil and Environmental Engineering, Engineering Education, Geosciences, Biological Sciences, Industrial Design, Biological Systems Engineering, Forest Resources & Environmental Conservation, and Crop and Soil Environmental Sciences mentor undergraduate researchers to conduct research on various interdisciplinary aspects of water sciences and engineering. The REU fellows get opportunities to conduct independent research and improve their communication (written and verbal) skills. Field trips and weekly seminars are organized to develop professional skills. Weekly social interactions are facilitated to enhance personal and professional bonding among REU fellows and with faculty/graduate students. The fourth cycle will be completed at the end of summer 2019.