water surface in reservoir may not submerge outlet enough for pressure flow

[l-man]

this warning 41307 comes up on every storm event. does anyone know why this warning occurs?

[mf78]

This error is generated when the orifice outlet is not sufficiently submerged. The equations used to solve for flow through the orifice assume submergence. You can use the culvert outlet option instead of orifice if you know the orifice is not submerged through the entire simulation. Culverts do not have to be submerged.