down slope flow paths from start point

[jamiefinney]

Is it possible using ArcHydro to specify some start points (manholes) and a DTM and have the downhill flow path created for each manhole? - i have approximately 10,000 nodes to analyse.

I've already managed to do this with the r.drain module in Grass but wanted to see if I could do it in Arc because i think it will be easier to automate in Arc than Grass.

Many thanks in advance

Running ArcView + Spatial Analyst 10 sp2 + latest ArcHydro Tools

[ColinConstance]

Hi Jamie,
I've been using TauDEM plugin (ver 3.1) for ArcGIS (9.3) developed by David Tarboton at USU. He has developed a number of specialist functions including 'Down slope influence' which does exactly (I presume) what you are looking for. It is limited to a grid size of 7000 x 7000 cells and it's accuracy is controlled by the accuracy of your DEM. I'm using it on 1-2m resolution LIDAR dems for culvert sizing.

www.hydrology.usu.edu/taudem/taudem3.1/index.html

It also has many functions that are similar to ArcHydro but is not really comparable.
Hope this helps....

Regards
Colin Constance