Closest Downstream Facility Table

Discussion created by ldahlin08 on Jul 6, 2011
Latest reply on Jul 6, 2011 by jsandhu-esristaff
Hello Everyone,

I am new to GIS and I could really use some guidance. I have been scouring the internet for hours but I just can't seem to find a good resource for what I'm trying to do.

What I have:
-Hydrologic data from the NGS which makes a network of rivers and streams.
-Facility coordinates and testing site event points (in two different shape and table files) that I have in effect snapped to the streams using "locate feautures along routes" in linear referencing. This gave each of my events a ReachCode corresponding to the stream it's on, which is basically like an address along the stream. The higher the "address," the farther upstream the point is.

What I need to do:
Create a table that gives each facility, the testing site that's closest to it, and how far away they are from each other.

What I've tried:
I think the "make closest facility layer" will do this for me. However, I don't think I am building my network correctly. What I did was select both of my shape files for the network in new->network in ArcCatalogue. But this didn't seem to be what I thought it would be because there was nothing for me to select in the make closest facility layer field. Imagine my facilities as accidents and my testing sites as hospitals. How do I set it up so I can calculate the route distance from "accidents" to my "hospitals." I would like to use the ReachCode as a cost feature to make sure that it is giving me the closest downstream point, rather than upstream.

Please, I clearly need help.