I am wondering about the best way to model a pond underdrain. The set up I am thinking of would involve a perforated pipe buried in gravel at the bottom of the pond, connected to an outlet riser and culvert. There are a few ways that I could see this modeled:
1)The “model everything approach” i.e. model the perforations as orifices which are routed to the pipe, which is then routed to the final outlet structure. I am usually dealing with existing infrastructure, and the level of detail required to model this accurately is usually not available. Also I have learnt that it is generally better not to make the model any more complicated than absolutely necessary.
2)Alternately, I could assume that the perforations will not be a limiting factor and simply model the underdrain as a single small orifice in the outlet riser. This begs the question about what the size of my orifice should be - the diameter of the perforated pipe? I have seen a couple models where a reduced orifice size was used, but I am unsure about how that size was reached.
3)The most common approach I have seen, however, is to completely ignore the underdrain when modeling ponds, which is not something I am exactly comfortable with.
Your assistance is much appreciated.
1)The “model everything approach” i.e. model the perforations as orifices which are routed to the pipe, which is then routed to the final outlet structure. I am usually dealing with existing infrastructure, and the level of detail required to model this accurately is usually not available. Also I have learnt that it is generally better not to make the model any more complicated than absolutely necessary.
2)Alternately, I could assume that the perforations will not be a limiting factor and simply model the underdrain as a single small orifice in the outlet riser. This begs the question about what the size of my orifice should be - the diameter of the perforated pipe? I have seen a couple models where a reduced orifice size was used, but I am unsure about how that size was reached.
3)The most common approach I have seen, however, is to completely ignore the underdrain when modeling ponds, which is not something I am exactly comfortable with.
Your assistance is much appreciated.