Williston Reservoir’s floating island appeared out of nowhere, vanished without a trace, then turned up 18 miles away still covered in mature vegetation and nobody at BC Hydro can fully explain how it formed or where it will drift next
Image generated with artificial intelligenceSometime around July 21, 2026, boaters on Williston Reservoir in British Columbia came across something that had no business being there: a landmass roughly the size of two football fields, covered in mature vegetation, sitting in open water where no island had ever been recorded. It wasn’t on any map. It had never shown up in BC Hydro’s satellite imagery. Nobody could say when it arrived — or how.
By the time the utility confirmed it was real, the island had already disappeared.
An island that shouldn’t exist
Boaters first reported the island on or around July 21, 2026, west of Finlay Bay on Williston Reservoir — a remote stretch of water in northern British Columbia, about 100 kilometers from the W.A.C. Bennett Dam. The landmass covered approximately two football fields and was blanketed in what looked like mature, established vegetation. That detail made it stranger. This wasn’t a loose clump of debris — it looked like something that had been growing for years.
The public interest wasn’t just about a strange natural phenomenon — it was about what might happen if that phenomenon kept drifting in the wrong direction.
BC Hydro spokesperson Bob Gammer confirmed the island’s existence after his team reviewed satellite imagery. The confirmation came quickly, and so did the disappearance. It had never appeared in any of BC Hydro’s prior satellite records, leaving the utility with no baseline, no history, and no obvious explanation.
Why a drifting island is more than a curiosity
Williston Reservoir isn’t just scenic backcountry water. It feeds the W.A.C. Bennett Dam, one of Canada’s largest earth-fill dams, on the Peace River. The dam’s Gordon M. Shrum Generating Station produces more than 13,000 gigawatt-hours of electricity annually — enough to supply more than a third of British Columbia’s total electricity demand. That’s not a minor regional facility. It’s foundational infrastructure for the province.
A floating mass the size of two football fields drifting toward intake structures or other critical components could create real operational complications. That risk pushed the story from local curiosity to national concern fast. CBC and Newsweek both covered it, and power industry publications took notice. The public interest wasn’t just about a strange natural phenomenon — it was about what might happen if that phenomenon kept drifting in the wrong direction.
Where did it come from?
BC Hydro opened the W.A.C. Bennett Dam’s spillways in June and July 2026 to manage excess water. A heavy winter snowpack combined with saturating summer rainfall had pushed reservoir levels higher than they’d been in some time — and higher water levels change what a reservoir can lift and carry.
According to Gammer, elevated water can free material that had previously been wedged along shorelines or settled into sheltered bays. Once buoyant, that material can drift. The leading theory involves logs and woody debris accumulating over many years in a protected area. As that debris slowly decomposed, vegetation may have taken root across the surface, eventually producing a stable, interconnected mass of plant growth and organic material capable of floating as a single unit. Unusual, but not impossible.
Gammer noted that vegetated floating islands of this size are rare in large reservoirs, though not without precedent. The exact origin of this one remains unknown.
Relocated — and still on the move
The island resurfaced — figuratively — on August 31, 2026, when BC Hydro identified it in a satellite image taken roughly two weeks earlier. It had traveled approximately 30 kilometers northwest of its original position near Finlay Bay, coming to rest against the shoreline of the Ospika Arm, around 280 kilometers north of Prince George and meaningfully farther from the dam than before.
Gammer confirmed the island appeared intact, consistent with how it looked when first spotted. Small aircraft and third parties on the water had also observed it independently. BC Hydro says the public is welcome to approach by boat or drone and photograph it, though climbing aboard isn’t recommended for safety reasons. Wind, not reservoir currents, is expected to be the primary driver of any future movement — and the utility says it doesn’t anticipate operational impacts given the island’s increasing distance from the dam.
What happens next
The island’s story isn’t over. It’s already proven capable of disappearing and reappearing, and there’s no guarantee it’ll stay where it currently sits. Wind patterns, water level changes, and the structural integrity of the mass itself will all shape where it ends up.
BC Hydro says monitoring will continue. The utility has been transparent about what it knows and candid about what it doesn’t — the island’s exact origin is still unconfirmed, its future path is uncertain, and whether it remains intact is an open question.
Two things are worth watching: whether the island holds together as a single mass or begins to break apart, and whether any future drift brings it back toward infrastructure. For now, it’s resting quietly against a remote shoreline — an anomaly that arrived without explanation, vanished once already, and could move again at any time.
Carlos is an engineer with strong expertise in technical and industrial topics. He previously worked at international companies such as Siemens and is multilingual.
