A floating island the size of a football field appeared unexpectedly - and then disappeared weeks later
A floating island larger than a football field suddenly appeared in the Williston Reservoir in northern British Columbia, Canada - and then, within a few weeks, simply disappeared. The massive mass, covered in trees and vegetation, was spotted floating in the water and documented by a boater, before the photos and videos reached Rocky Avery, a local resident, who posted them on social media.
A floating island larger than a football field suddenly appeared in the Williston Reservoir in northern British Columbia, Canada - and then, within a few weeks, simply disappeared. The massive mass, covered in trees and vegetation, was spotted floating in the water and documented by a boater, before the photos and videos reached Rocky Avery, a local resident, who posted them on social media.
"It was a pretty amazing sight. I've never seen anything like it in my 40 years in this area," said Avery. According to him, he decided to share the footage also because a large fishing competition was about to take place in the area, and he wanted to ensure that the participants were aware of what was floating in the reservoir. "And I wanted BC Hydro to know it was there, in case it started floating towards them."
BC Hydro, the British Columbia electric utility, didn't know what to think at first either. Company spokesperson Bob Gammer said that in an era where it is easy to create images and videos using artificial intelligence, it was initially difficult to understand if it was a real phenomenon at all. But satellite images from July 21 removed the doubt: the island was indeed there.
The satellite found it - and then lost it
According to BC Hydro, the floating island was located in the main body of the Williston Reservoir, west of Finlay Bay and about 100 km west of the W.A.C. Bennett Dam. It is estimated to have been about 70 meters wide and 140 meters long - an area of about 9,800 square meters. For comparison, this is an area larger than a Canadian football field and almost the size of two NFL fields.
But when company personnel returned to check the area, the picture had changed. By August 5, the island no longer appeared in the satellite data.
"We took more updated photos and we can no longer see the object. So now it's gone," said Gammer. However, according to him, this does not mean that the island necessarily sank to the bottom. "It's possible it returned to a more protected area along the shoreline."
BC Hydro estimates that the island is not expected to affect the operation of the reservoir or the dam, but they continue to monitor the possibility that it will appear again. Due to the massive size of the Williston Reservoir, ongoing monitoring from the water is not practical, so the company relies, among other things, on satellite imagery and reports from the public.
So where does a whole island floating on the water come from?
Gammer has at least one possible explanation. According to him, it is possible that the island was formed over years in a certain area along the coast, where tree trunks and plant debris accumulated. Over time, the organic material decomposed, plants took root on it, and even trees managed to grow - until a large and stable-looking mass was created.
This year, the Williston Reservoir filled to the brim after a snowy winter and prolonged summer rains. The high level forced BC Hydro to open the dam's spillways in June and July to release water.
According to Gammer, the reservoir hasn't been this full in 14 years. One possibility is that the unusual rise in the level dislodged the plant mass from its place, and then the winds pushed it into the open water.
"We can't determine for sure where the floating island came from, but it's an explanation that seems plausible," he said.
Avery also said that the high water level changed the area significantly this year. According to him, sand dunes along the coast that were previously used for off-road vehicle driving were washed away, and larger than usual amounts of trees and debris were swept into the reservoir. "There are areas that we wouldn't even drive a boat through before, and now we are sailing right over them."
And it is definitely not the only floating island in the world
Although it is a rare sight in the Williston Reservoir, floating islands are not an unknown phenomenon. They can form when layers of peat, vegetation, and organic material detach from the bottom or a shoreline and begin to move on the water's surface.
In Lake Chippewa in Wisconsin, for example, floating peat islands were created after the area was flooded following the construction of a dam. One of them, known as the "Forty Acre Bog," is so large that every year boats are needed to push it and keep it away from a nearby bridge.
In Lake Victoria in Africa, floating islands and their impact on transport, fishing, and water quality are also being studied.
As for the mysterious island of the Williston Reservoir, as of now, no one knows for sure where it is. It may have sunk, it may have reattached to the shore - and it may still be floating somewhere in the vast reservoir, waiting for someone to notice it again.
