It has been unsuccessful in preventing people reaching the falls via a track and ladders around the top by the station's water intake, emerging at the deck next to the powerhouse. The most dangerous part of the access was a 70-degree slope ending with a 12m fall onto rocks.
Gates and fences erected by the council to the track had proven no barrier to determined young people for whom the pool at the bottom of the falls was an irresistible attraction.
Mr Aitken said they would continue to try to restrict access to the falls this summer until the council had ruled on the feasibility of options.
He said public safety was a major concern even if people were allowed to access the powerhouse deck via the steep narrow steps through the tunnel. There was also the issue of the drop down from the deck to the pool.
Power station lessee Michael Davis said he could not believe the risk that young people were taking to reach the bottom of the falls.