Junction loss Across catch basin with sumped bottom

[Brian_PE]

I'm looking for any info on calculating the junction loss across a inlet box with a sumped bottom. We received a comment for the Township requesting specific loss value. I currently have the pipes modeled in Hydraflow/Civil3D and have no way accounting for the basin invert depression.

Any info would be appreciated.

Thanks

 

[Akel]

Refer to HEC-22 section 7.1.6 for information on energy losses.
Link

It seems that hydraflow calculates junction losses based on the "Approximate Method" (Sec 7.1.6.6) and does not account for benching.

 

[Brian_PE]

I think you're correct. I think I found a work around, so hopefully the county buys in on it.