Finding the watershed of a point

[Anonymous]

Hello, 

I have  a  TIN surface generated from a Lidar point cloud. Using the newly created contours or the Lidar points, I would like to be able to find the watershed of a point on that surface. Is this a capability of Civil 3D ? 

Thank you for your help !

[Anonymous · Accepted solution]

By selecting the surface, the Surface Ribbon becomes active.  Select Catchment Area under Analyze, and choose your point.  C3D will analyze the runoff and show you the surface drainage area that drains to that point. 

Alternatively you can place a bunch of Water Drops and trace around them, but that's not very accurate.

[santhoulakis · Accepted solution]

What James previously suggested is what I would also do.

Yet, especially for a non perfect surface, the presence of many small negligible catchments is difficult to avoid and should be taken into account before defining the substantial catchment boundaries. 

Of course, it all depends on the degree of accuracy one needs to achieve.

[Anonymous]

This is the issue I have run into. Currently the federal government needs my department to delineate the catchment area for all of our outfalls. It would have been too easy if this tool worked in a manner more consistent with doing this by hand.

Thank you for your help

[santhoulakis]

I believe this video https://www.youtube.com/watch?v=nhDlQirHERA could give you some more help.