The city has stepped in to take over a project at McLean Mill, after rust water started flowing down Kitsuksis Creek.
City CAO Tim Pley said volunteers were drawing down the mill pond in order to work on a sluice gate when the water turned dark red.
Members of the Alberni Valley Enhancement Society began drawing down the log pond, when long-buried iron came in contact with the air, causing the release of iron oxide and a massive algae bloom.
People living downstream from McLean Mill were advised to not use any well-water, or water from the creek for irrigation
McLean Mill Society has temporarily closed access to the buildings, since the fire pumps are not working due to the draw down of the mill pond.
Pley says overnight rains are beginning to refill the pond and it has already become significantly clearer this morning.
He said there will be a cost to the city, which wasn’t part of the budget, as the McLean Mill National Historic site is on city land.