Back when the US first started fighting in Afghanistan, there was a news article about
the Afghans fearing we would damage the "qanats" and badly hurt agriculture. I posted
about it then, but I just saw an "engines" episode # 1250, which tells quite a lot
about them.http://www.uh.edu/engines/epi1250.htm

Very interesting constructions and term, Bill. Some of the pits and horizontal spring caves in the limestone regions of the southeastern states could be said to be natural qanats. If I find an unnamed cave that takes the classic form I'll put it on the survey as a "qanat.

My, Dr. Bill, that's very interesting. Never heard of such a word. Thanks for the webpage. I was hoping to get into the 'speleogenisis' thing (at some point), and I guess this comes close (at least we're going under ground here). Fascinating....I have a poem about the 'aquaduct of the mind.....' that came out as I thought about those ancient waterways and the way it reminds me of following the currents of someone's thoughts. This takes a whole new direction, deep under the desert sands...