1.  flume(n = noun.object) gulch - a narrow gorge with a stream running through it;
is a kind of gorge

2.  flume(n = noun.artifact) - watercourse that consists of an open artificial chute filled with water for power or for carrying logs;
is a kind of watercourse, waterway

   A stream; especially, a passage channel, or conduit for the water that drives a mill wheel; or an artifical channel of water for hydraulic or placer mining; also, a chute for conveying logs or lumber down a declivity. [1913 Webster]

flume, n. & v.
--n.
1 an artificial channel conveying water etc. for industrial use.
2 a ravine with a stream.
--v.
1 intr. build flumes.
2 tr. convey down a flume.

Etymology:
ME f. OF flum, flun f. L flumen river f. fluere flow

N  conduit, channel, duct, watercourse, race, head race, tail race, abito, aboideau, aboiteau, bito, acequia, acequiador, acequiamadre, arroyo, adit, aqueduct, canal, trough, gutter, pantile, flume, ingate, runner, lock-weir, tedge, vena, dike, main, gully, moat, ditch, drain, sewer, culvert, cloaca, sough, kennel, siphon, piscina, pipe, funnel, tunnel, water pipe, waste pipe, emunctory, gully hole, artery, aorta, pore, spout, scupper, adjutage, ajutage, hose, gargoyle, gurgoyle, penstock, weir, flood gate, water gate, sluice, lock, valve, rose, waterworks, pipeline, vascular.