What are the pros and cons of using digitized direction as compared to sources and sinks for setting the flow direction in a sewer or storm drain network?
We have coverage data where the digitized direction matches the flow direction. We are migrating to ArcSDE. The points that I can see are:
1. Digitizing new features in the downstream direction will take more work.
2. Setting the flow direction to the digitized direction can only be done through a geoprocessing tool, not the Utility Network Analyst toolbar.
3. Using sources and sinks seems like it could be more flexible.
4. Using digitized direction seems like it would be more reliable, since the flow direction of a feature doesn't depend on the rest of the network.
Are there any other pros and cons that anyone can think of, particularly related to hydraulic modeling software?
I would trust the directions that you have...largely, because if they were wrong, I am sure you would have heard about it and any errors corrected. With regard to your other points, you would have to weigh the number of new additions to the existing dataset against setting up a workflow to automate the process.