Temporary fencing has been in place around the Mt Cargill tower since December while upgrades were completed, although it had been expected to be removed in May.
Telecommunications company Kordia, which manages the site, said it was considering establishing permanent fencing around the tower to "enhance security and safety".
Crush the Cargill organiser Steve Tripp said while the change would hinder trail running events, he was more concerned about the impact on members of the public.
Previously, people could walk under the tower, which has barriers around each leg.
"I've been up there on nice days and there's been a queue at both ends of this little track. People trying to clamber around holding on to the fence and sliding all over the place because they're just not used to that kind of terrain — it's pretty rough and muddy," Dr Tripp said.
"It’s a really good asset to the city to be able to get up there and have a look at the view and it's been destroyed."
When the Otago Daily Times visited the site yesterday, a section of fence next to the path had fallen.
If the fencing became permanent, Dr Tripp wanted Kordia or the Dunedin City Council to create a track around the edge of the fence.
"Not many cities have such a stunning view so close to the sea ... but it's not very well utilised because of access problems like this."
3 Peaks Mountain Race race director Lydia Pattillo said the impact went beyond trail runners and she had seen tourists and people in wheelchairs struggle to navigate the site.
A Kordia spokeswoman said installing permanent fencing to boost security and safety was still in a planning stage "with no firm date set".
She welcomed public feedback on the proposal.
"We acknowledge the public often access the areas below the tower and we’re working with local authorities to ensure the fencing design minimises disruption to recreational activities and public enjoyment," she said.
"The Mt Cargill site houses critical broadcasting and communications infrastructure and permanent fencing will help protect both the transmission equipment and the public from potential hazards, such as falling ice that forms on the tower during winter."
There was also evidence that members of the public had attempted to illegally climb the tower, which put them at risk of injury or death, and of exposure to harmful radiation, she said.
