Orifices and weirs is online: the free geoapp for flow through orifices under head (sharp-edged free or submerged, thick wall, large orifice, sluice gate) and over weirs (Bazin, Rehbock, SIA, Francis, Cipolletti, Thomson, broad-crested), with tailwater submergence. For each case you get the discharge, the required head or the size; dimensioned sketch, comparison between cases, rating curve, PDF report.
