Creating a middle path from a irregular selection

[DiceMan321]

Hello!
I got myself in a pickle so large than I proceed to create an account and write this post on this forum. I'm trying to modify rivers in a map that I'm creating. 
Here's one of the rivers: 
https://imgur.com/a/C5I4Inz 
I came across this post, whos OP got a similiar problem: 
https://www.gimp-forum.net/Thread-Creati...-selection
Although the answers were nearly at home of what I need, unfortunately, because of the shape of the rivers I couldn't use answer provided in that post. 
That's why I'm asking. Is there a way to create a path going thru the center of the rivers? 
PS: sorry for any spelling errors, English is not my first language and I wrote this post in a hurry. 
Thanks in advance for any answers!

[Tas_mania]

I duplicated the layer and selected by color. Then Select > Shrink by 1 pixel. The small rivers are only about a pixel wide anyway.

[PixLab]

(06-13-2022, 12:09 AM)Tas_mania Wrote: I duplicated the layer and selected by color. Then Select > Shrink by 1 pixel. The small rivers are only about a pixel wide anyway.

I would just add, then Shift + click on a node/control point or a path line with the path tool, to remove the one you don't want.