Ryszard A. Daniel, PhD., PE, senior consultant and design leader of Rijkswaterstaat (NL), recently retired and founder of a consulting company, is a designer, construction supervisor, project leader and reviewer of infrastructure projects, largely hydraulic, in The Netherlands and other countries. Timothy M. Paulus, PE, senior mechanical engineer for US Army Corps of Engineers, St. Paul District, is a senior consultant, supervisor, project leader and reviewer of hydraulic projects in the USA and other countries.