This subseries documents Simons' participation in various water- or engineering-related conferences or committees. Items here were retained only if they pertained directly to Simons' participation. Presentation titles and abstracts are frequently present. The organizations most represented in this subseries are the Congress of the International Association for Hydraulic Research, the American Society of Civil Engineers (ASCE), and the International Standards Organization (ISO). The latter grouping of files, which relates to Technical Committee (TC) 113, Liquid Flow in Open Channels, seems to have come to Simons from Alvin G. Anderson (AGA) at the University of Minnesota, perhaps when committee membership changed. Also included in the subseries is a folder on the D. B. Simons Symposium on Erosion and Sedimentation, held at CSU in honor of his retirement. The major material types in the subseries are correspondence, conference programs, and reports. The files are arranged in chronological order, with the exception of the ISO files, which were kept together as a group at the beginning of the subseries.