Origin of Karez

There are over 1,000 karezes in the region of Turpan and 436 of them are in Turpan County, almost half of the total number. In Shanshan County there are 396 karezes. The least number of karezes are in Toksun County but that number is still over 160. The total amount of water run out of these karezes reaches more than 500 million cubic meters, exceeding the total volume of the water system in Flaming Mountain.