There was a huge effort by the DWR, Wildlife Groups, and the Grouse Creek Recreation District to bring fishing back to Etna. The Etna Reservoir and the immediate area surrounding it is privately owned by a private water company. Since it is privately owned, they have to agree to allow the public to access the area. Because of concerns about public use of the area, an agreement couldn't be reached.
Private fishing cannot be allowed because the reservoir is on a pre-existing stream. The state of Utah will not provide a private pond permit for any reservoir on a pre-existing stream.
Majority ownership of the water company is currently Darrel Nelson with Milt Oman as the President. Until the ownership of the water company changes their stance, public or private fishing will not be availble. Hopefully this will change sometime in my lifetime.