End overfalls can often be employed as a substitute structure for discharge measurement at locations previously not having been considered. In this chapter the current results are reviewed for the rectangular- and the circular-shaped end overfalls. Answers are given to questions such as: What is the discharge for a certain end depth, and Is the end depth a sufficient parameter for discharge determination?
In addition, nappe geometries originating from ducted outflow into the atmosphere are presented. Further, nappe differences between laterally guided and discharging freely into the atmosphere are given. Effects of roughness are discussed, and the transitions from pressurized to free surface flows in a pipe are reviewed.