SEEP/W What boundary condition should be used during a steady state seepage model of a dam.

ChrisBawden

Hi I am a practicing Dams and Tailings engineer from Australia, routinely I measure seepage flows out of a dam however there is confusion within my industry about what boundary condition should be applied to the downstream area. In reality most flow does not rise to the surface and travels in the foundation downstream. What boundary condition is used to estimate flows out of the model? Potential seepage face is unsuitable and fixing a downstream head does not allow the model to determine the appropriate water level.

KathrynDompierre

I agree - setting representative boundary conditions is often a challenge. While the potential seepage face boundary condition is often used to represent conditions on the downstream face of a dam, I agree that it is not the boundary condition appropriate for the downstream portion of the domain. Typically a total head boundary condition is applied along the downstream side of the domain given the observed conditions (e.g. downstream reservoir water level). This allows SEEP/W to compute the corresponding flow through the domain and out of the downstream nodes.

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