[potac]

I am having a domain with an outlet to water. Water enters the domain through the inlet, fills partially the domain and leaves through the outlet. Part of the outlet patch is flooded by water from outside thus influences the outflow. I have translated the geometry so the water level outside the outlet corresponds to 0 m level. However, I cannot figure out the correct BCs for the outlet from the tutorials. It should involve a hydraulic pressure, isn't it? I have tested for example phaseHydrostaticPressure but unsure it is the right way.

Inlet:
U: flowRateInletVelocity
p_rgh: fixedFluxPressure
alpha.water: fixedValue

Outlet:
U: zeroGradient
p_rgh: prghPressure
alpha.water: zeroGradient

Any suggestions?
(OpenFOAM 5, interFoam)