Ancient canal systems are everywhere in the Middle East.
However, in the case of the Afghani qarez - what is elsewhere called a qanat or a foggara - large portions of the preexisting underground canal system have been entirely destroyed. Decades of warfare, neglect by the Taliban government, and now the War on Terror have all but erased the ancient system. Newer pipe-driven systems, such as those installed by local dispatches of the Czechoslovakian Provincial Restoration Team have taken their place.
It's a good question as to whether or not these pipe systems will survive on departure of coalition forces from Afghanistan. Previous efforts to install modern wells and other amenities have encountered issues with lack of parts, lack of expertise to fix the new infrastructure, and even opposition from confused and understandably paranoid locals.
Hat tip to an unnamed linguist currently dispatched in Afghanistan and various articles on the installation of modern pipes systems in the Afghan outback.