Intersecting Rivers through Open Space - Gap problems

[MelissaMitchell]

I'm working in ArcGIS Pro. I want to intersect river segments (lines) that go through Open Space (polygons). The problem is that some areas of the river are wide so there are gaps between the river and open space. I created a buffer (100ft) that would capture gaps with Open Space. The buffer did a good job capturing the missing open space. I then did an intersect on the Buffer and Open Space so that I only had those sections of overlap. I want to intersect the Buffer (with open space) with the River (lines) but again I have gaps so I'm missing the river segments where there is open space.

What tool should I be using to find River segments (lines) that cross Open Space (polygons) if there are gaps?

I've included a map of the problem.

Thank you!

[DanPatterson]

It is hard to tell from the images but perhaps if the buffer and open space are both polygons, then

Symmetrical Difference (Analysis)—ArcGIS Pro | Documentation

will identify the areas that don't overlap

Computes a geometric intersection of the input and update features, returning the input features and update features that do not overlap. Features or portions of features in the input and update features that do not overlap will be written to the output feature class.

[MelissaMitchell]

Thank you so much for replying!

The Buffer and Open Space are both polygons. My goal is total stream length (line) protected by open space. 

Would using Symmetrical Difference with the buffer and open space would give me areas that don't overlap right? I want where they do overlap even if there is a gap between stream line and open space. I've never used Summetrical Difference so if I have it wrong please let me know.

Thank you for your time!

[DanPatterson]

You already have the areas where they overlap.

Sym Diff gives you the areas where they don't overlap.

Give it a shot.  It won't alter your input data and if it is successful in identifying the areas you are after, then you can "Merge" both sets of data to a new file.