I couldn't find much about this other than the usual 1:1 Upstream and 2:1 Downstream ratios (which most seem to show examples with 0 skew), so hopefully someone can help me. When you have a channel that is skewed to the roadway embankment, is the 1:1/2:1 perpendicular to the embankment or the channel? For example if you use the 1:1 upstream and the channel is skewed to the embankment 45°, then your ineffective flow is essentially at the same location on one overbank for all cross sections.
Attached is a picture of our survey file and the red lines are the construction lines for the 1:1/2:1 ineffective flows. Flow direction is up and the channel on the left of the upstream junction is not modeled due to its very small flow change, so only the channel that flares to the right on the picture is modeled. Its not that the structure is skewed, but once you get 100' or so away from the embankment it has a skew.
Attached is a picture of our survey file and the red lines are the construction lines for the 1:1/2:1 ineffective flows. Flow direction is up and the channel on the left of the upstream junction is not modeled due to its very small flow change, so only the channel that flares to the right on the picture is modeled. Its not that the structure is skewed, but once you get 100' or so away from the embankment it has a skew.
