In order to ensure that you are able to accurately represent ecological practices on the stream network, we must ensure that the stream network extends high enough. In some cases, you may find that you want to extend the network.

If so, you have two options:

You can start over and re-delineate your flow network using a lower area threshold, but if you rerun that tool, that means that everything that you originally changed to a 1 is going to go back to being a 0; so we don’t really want to do that.
You could create another area threshold network, giving it a different name. Select the section that you want to add to your current flow network, and, using the append tool, add it to your original area flow network.

DO NOT digitize what is missing. Never go in and manually draw a line that you would add to your area flow network. It won't align to your LiDAR derived flow direction, and therefore you will not be able to run future tools to get your stream reach.

Stream Networks.JPG

While it is a time-consuming process, it’s very important that you do take your time through this and make sure that you’ve got every segment that you think could be part of the perennial network.

Using the recommended add-ins will help you to get an oblique view. They will allow you to see if channels are real and should be included in your network or just shadows.