There are several separate problems here.

One is "People don't like bags stuck in the branches of trees and clogging waterways in their parks". Lightweight plastic shopping bags are so thin that a light breeze can pick them up and loft them up into the air easily. They cost approximately nothing - <2 cents retail, significantly less in bulk. It is incredibly expensive by comparison to pay someone to remove them from tree branches and riparian zones - tens of dollars in wages, equipment, and liability insurance. This is a pragmatic reason why municipalities passed bag taxes or bans. Forcing people to use paper or heavier-weight plastic bags that don't blow in the wind, even if they're not in practice "reusable", solves this one. Taxing them 5 cents or 10 cents or 25 cents per bag nudges a high percentage away.