For decades Calgarians called the weir system, now known as Harvie Passage, a drowning machine.

Now officially open, it’s been totally rebuilt with drops so that experienced paddlers can enjoy Class 2 rapids in the heart of the city.

But the fire department’s Deputy Chief, Len MacCharles, warns experience is key.

He’s worried rafters and revellers going down the river may get in over their head.

Record snowpack is going to make for fierce currents and glacial temperatures in the coming weeks, said MacCharles.

Portage spots are clearly marked but anywhere beyond that point people could be in for a deadly ride, he warns.