Contours from LDD 2007

[JoeBubba]

I have just started using LDD 2007. I created a surface using a point file given to me by the surveyor. I then created a countour file using the surface but my contour does not match the contour file given to me by the surveyor. The minor and major contours match but my contour files has a whole bunch of localized depressions. Any thought anyone?

 

[LHA]

Did you run your contours to a smaller interval than the surveyor did? If he was running 2-footers, and a point was just 0.5 feet low, the next minor down might skim right over it, or show just a slight dip in the land surface. If you ran 1-footers on the same DTM, that same 0.5 foot dip would show up as a closed depression.

Both results are technically correct. It is up to you (or the surveyor, whoever is sealing the topo) to change the finalo basemap to accurately reflect what is on site. Are these low points slight dips/swales, or are they actual holes?

Engineering is the practice of the art of science - Steve

 

[JoeBubba]

Thanks. I went into the point file since posting, like I should have - feeling like a rookie, I found a bunch of points with 0 elevation and those are what's busting my contours. Thanks.

 

[BelspringKen]

Sounds like you figured it out on your own - not too shabby!