You could create steps so to speak. So across the river there would be bubble lines that are only 20% or so of the span. Then the plastic would step down unti

You could create steps so to speak. So across the river there would be bubble lines that are only 20% or so of the span. Then the plastic would step down until it reaches the other side and fish could swim around the bubble lines. I realized I probably didn't describe it well... he's a drawing of what I mean https://imgur.com/a/n9PdT0L https://imgur.com/a/n9PdT0L