How do you create upstream buffers at a specific distance from another polygon?

Question

ArcGIS Pro / ArcMap Licenses: Spatial Analyst, 3D Analyst

I'm working on a project in the Daniel Boone National Forest to create critical habitat areas in order to keep roadside pesticide applicators away from sensitive areas.

As part of this analysis I need to create buffers around streams a specific distance upstream from another stream buffer polygon layer that overlaps with a stream line. There are 15,000+ different stream segments (blue lines) and about 150 existing stream buffer polygons (red lines) I'm working with here.

Essentially, I'm trying to use these existing 150 stream buffers and extend them upstream 1/4 mile. This has to include any lower stream order branches that split within that distance.

I have done some research that led me to the idea this workflow will involve the Flow Direction tool and potentially some stream network analysis.

However, I've never done an analysis like this before and I'm not sure how to stitch these different tools together to get the output I'm looking for. I'm hoping someone here might be able to help.

Answer 1

I being the author behind RivEX would suggest you use the Extract nearby tool to answer your problem, you can read about the tool in the help file here.

Assuming your network is topologically correct and fulfils the input requirements of RivEX. Then a workflow would be:

1. Prepare your network with RivEX and encode into the network distance to mouth
2. Intersect your buffers with the network to create the starting points
3. Transfer the distance to mouth to the points
4. Sort points by buffer ID and distance to mouth and keep only the point for each buffer that is furthest away from mouth, this will by your upstream point
5. Feed remaining points into Extract nearby tool and ensure you chose optional buffer.
6. Optionally dissolve into your existing buffer.