Rainwater capture isn't about you and I and some 50-gallon drums, your article even talks about reasonable use. The idea is to stop assholes from changing/diverting waterways.

There was an ass somewhere out West that was prosecuted, acting like he was a simple man getting the government shaft. He was collecting so much he dried up a creek that downstream farmers depended on.

Funny enough, I looked up Florida and apparently we not only encourage rainwater collection, some municipalities offer incentives! Weird. Now if it would only rain...