Watershed Analysis in C3D 2013

[sfore]

I created a surface from Lidar data and I'm wanting to show 1 large watershed for an area on my site that I can visually look at my contours and see where the water is draining too.  I don't want to show every single watershed that displays when I turn on watersheds in surface styles. I also tried the watershed analysis in surface definitions, but I don't quite understand what the merge is doing plus there's hundreds in the range details.  It seems like several versions back, you could fine tune your watershed areas to gather larger or smaller areas.  Its been a while since I've messed with watersheds.  Any help is appreciated.

[Joe-Bouza]

I havent used the WSA its always been nebulous to me even back in LDT. I think thats a common perception.

does the catchment object help you out at all?

Catchments

[sfore]

Yes, the catchments sort of helped, but I was wanting the overall watershed for a large portion of the site, not each and every watershed or catchment area.  Last Friday was the first time I've ever used catchments.  I first did a water drop on several areas of my site.  Then I created a catchment group.  Then I created a 'catchment from surface' and clicked on the end of where the water drop stopped.  It gave me a magenta boundary with related label and a blue flow path with related label.  This is good, but I was hoping by turning on the watersheds or performing a watershed analysis, would show the overall (1) watershed boundary for the whole hillside.  Maybe I'm wishing for too much for the watershed tools.

Also, in regards to catchments, if I change the runoff coeffiecient inside the catchment properties, the TOC (time of concentration) doesn't change.  It seems it should change.  I first ran the catchment with 0.50 as coefficient.  I went to catchment properties to change coefficient to 0.35 and then again to 0.25 and the TOC remained the same.  Is this something that SSA fine tunes and will show differences?

Thanks, Shawn