flume

noun

1. A ravine or gorge, usually one with water running through.

   “Near the upper end of the portage the river falls 100 feet in as many rods, the water going at lightning speed through a natural flume in the rock. So rapid is the descent that the water in the flume is but 3 feet deep. We named this the "Devil's Slide."”

2. An open channel or trough used to direct or divert liquids, especially to carry materials (logs, mined material, etc) or people (as a water slide), especially (but not always) one where the walls are raised above the surrounding terrain rather than recessed like a ditch.

   “[...] the flumes are generally not dark rides and they run much faster. Two notable exceptions are the Timber Mountain[…]”

verb

1. (transitive)To transport (logs of wood) by floating them along a water-filled channel or trough.