First a disclaimer: I have very little experience with ArcGIS, I usually use QGIS and only recently started using ArcGIS Pro.
My goal is relatively simple: Creating a polygon that follows the outlines of this river line with variable thickness.
At first i saw two main ways of doing it:
1) Simply creating a polygon and drawing it (using the Freehand tool) so that it follows the outline of the rivers, however this is time consuming, and the fact the size of the river change when zooming prevents accurate drawing.
2) Exporting the river alone as a raster, then creating a polygon out of that raster, however I would have to reasign coordinates for this new polygon, which would bring some inacuracies.
-- Most of the Internet tutorials i saw recommended using the "Construct Polygon" tool, however it doesn't work on unclosed lines, and it only creates polygons out of the few rivers that join back. (Exemple here: https://i.imgur.com/CrTByTD.png https://i.imgur.com/ipt5hK8.png )
Is there a way to directly (as automatically as possible) create a polygon out of the shape/outlines of these river line (with their symbology) without either having to draw polygons by hand or exporting it as a Raster image.