AutoCAD Civil 3D

[#1]

I have 2 feature lines, one is at elevation 132 (TOB), and the other at 123 (TOE).  I inserted elevation points at an increment of every 3 ft., which should make a smooth arc of contours around the pond.  Not the case.  How do I fix the issue I am having?  See pic below...

 

[#2]

Is your surface set to use a maximum triangle length?

[#3]

Switch your surface style to display the TIN lines.  The rules of Delauney triangulation generally force the surface to connect surface points to their nearest neighbours, so in this case you likely have lines running across the inside of your curves, instead of from the inside to the outside featureline.

[#4]

[#5 · Accepted solution]

The quick way to fix this is to add them to the surface definition as contours making sure to minimize the flat areas. If you add them as breaklines you will be flippin' all those edges.

[#6]

... you will have fewer triangles to flip and a better performing surface if you remove all those elev points.

[#7]

It's not allowing me to add the feature lines as contours...

[#8]

Oh that's a bit of a bummer. I do use simple plines for basin & bld pad surfaces quite often. Not the greatest solution but if the basin was disconnected from the rest of the design it may not be a big deal losing the dynamic capabilities.

The other option is flipping the edges. In both cases I would remove the elv pnts.

[#9]

A grading (I don't like these) or corridor are other options but it does not look like the top and bottom outer curves have the same radius as the offset. The lack of symmetry makes these options tough.

[#10]

I did remove the elevation points.  I exploded the feature lines and added the poly's as contours.  MUCH more control this way.  I will have to remember this workaround.  Thanks for the info!!