Do you understand that you don't own the surface water flowing through your property, you can't just damn it and grab it, and that it's always been that way?
You dumbass! Once the pond is full the water flows over a spillway and continues to flow down stream.
The water on spills over the spillway and flow downstream when a specific amount of water is allowed to accumulate in the reservoir. During droughts the land owner could prevent any water from flowing downstream.
The point is that the water passing through the owners property is not the owners property. It is a shared resource by all the communities it flows through and impacts from it's source to it's end. Centuries of established law gives ownership of the water to the public.