A legal question about business.... who controls the right of use of the water and it's currents below a dam ?

Question

Both sides of the river are national or county park lands.

Answer 1

Multi-jurisdictional question, depending on how much water and what "use" you're referring to (power, boating, access, etc): federal and state laws authorized federal and state agencies to have overlapping and complementary say in different parts of your question. Federal and state energy, federal and state environment, federal and state navigable waterways, state and federal regulations regarding waterfront parks, etc.

Answer 2

THE MOON CONTROLS WAVES :-)

Answer 3

That is no matter ,its water for nature and currents for who made the dam

Answer 4

Usually the state PUC or Water authority controls and leases water rights.