Its a flume My dictionary defines a flume as "a chute or trough for carrying water, used as a source of water power, to convey logs, etc." The flumes in the Sierra were built to transport water to where it was needed (for irrigation, domestic uses, industrial uses, power generation, etc.) and/or transport logs.. Flumes are still being used to carry water in the Sierra. Brave or foolhardy people sometimes used them for transportation. The book The Pacific Tourist originally published in 1884 (I have a 1970 reprint) has a description of a ride on a log flume.
The V & T did not run to Truckee CA. The Truckee in the name refered to the Truckee River. The V & T interchanged with the Southern Pacific east of Reno at Mound House NV
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.