I am modeling a rural irrigation system, and the way the system is designed, they have placed stand pipes in the the sub-laterals that have weirs built into them. The weirs act as a kind of pressure sustaining valve, and force the upstream HGL up, and don't allow water to move down stream unitll the water spills over the weir. I have tried modeling this with a PSV, but the on-off nature of the valve isn't working for me. Does anyone have any suggestions as to how I can model this weir in EPANET?
--the Uncvil Engineer