This isn't as bad as it sounds. Water prevented from reaching the ground in watersheds means groundwater doesn't get replenished. Now maybe a house here and there collecting rainwater isn't a problem, but what about Nestle? The law should allow reasonable rainwater collection by individuals or family households while preventing theft of water from a region.

Rainwater collection laws in the US are based on conservation and fair allocation of a scarce resource.

In places that don't have scarcity, you actually have the opposite issue, where drainage might be restricted or mandated to prevent issues from harming your neighbors.

I can't build a dam on my property because it might flood my neighbor. People in the southwest can't collect water at will because it might dry out their neighbors.