Large areas of woodland near to the airport would be need to be removed for the runway to be built.
After the plans were approved environmental protesters arrived at the site and set up multiple camps.
One of the protestors, Martin Porter who was 27 at the time, was among those that dug tunnels at the site.
The protesters were soon joined by a environmental activist named Swampy, real name Dan Hooper.
“All the time we were there we had the media, we had Swampy, we were able to give our message that this is a terrible idea, 400 acres of green belt disappearing,” Porter said.
After six months the group were finally evicted.
Local resident, Jeff Gazzard, who was also among the protesters, said the national media attention helped to bring environmental issues into the mainstream.
“Climate change began to be an issue then, but it wasn’t the headlines it is today,” he said.
“A lot of things have changed in terms of our understanding of the environmental impact of a major airport.”