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I'm working on a project where I need to snap an existing line layer to a different line layer. These lines represent streams and rivers. I'm working within QGIS Maderia 3.4 LTR.

I've tried using the "Snap Geometries to layer" tool but it doesn't appear to snap the input layer to the reference layer, the input layer continues to stay in the same position, no matter the tolerance I put in (10ft, 15ft, 100ft, 500ft).

I've figured out that I can use the vertex tool, enable snapping and manually do a lot of it. With the snapping and the vertex tool, I've played around with the type also (vertex, vertex and segment, segment).

With the manual snapping, I've been having particular trouble with the confluences, where one stream merges with another. This is an area of the snapping that especially needs to be done precisely. If this process does need to happen manually, any hints for that particular task?

The dataset is large and I was hoping to find a less tedious process. Especially since I need to be able to snap or create a snapped layer to within a 15ft precision level (currently with the manual snaps, I've been using a buffer as a guide).

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    What behavior are you using with the Snap Geometries To Layer processing algorithm? These can have a profound effect on the results. – Saijin_Naib Nov 5 '19 at 23:11
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    Not the solution that you are after but you can also enable tracing along with snapping to quickly digitise the lines. – MapInfoNewbie Nov 5 '19 at 23:30
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    @Saijin_Naib I've been using the behavior "prefer closest point, insert extra vertices where required"... Do you recommend one? I haven't tried others yet, I will tho, thank you for that! – Cocofish Nov 6 '19 at 15:53
  • @MapInfoNewbie I've definitely thought about that! The project tasks specified for snapping so I haven't gone that route yet. Waiting to hear back if that could be an option from the PM! – Cocofish Nov 6 '19 at 15:55
  • @Cocofish, I've had to resort to a few multi-pass corrections in the past. In one instance, I started with Move End Points Only, prefer aligning nodes with an appropriate tolerance, and then switched to prefer aligning nodes, insert extra vertices where required and ran that a number of times. Can you attach the data? What CRS are you using? It sounds like some sort of local state plane to be in ft. – Saijin_Naib Nov 6 '19 at 15:59

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