A close cooperation between UNESCO-ICQHS (International Center on Qanats and Historic Hydraulic Structures) and the Iranian Organization for Cultural Heritage eventually resulted in the Persian Qanat being put on the UNESCO World Heritage List. UNESCO-ICQHS proceeded to single out 11 qanats from among some 37000 qanats in Iran according to some technical criteria, and then conducted a series of studies on the nominated qanats. The results of those studies made up the content of a dossier which was later submitted to UNESCO for their appraisal. UNESCO-ICQHS always stood by the Iranian Organization for Cultural Heritage during the process of this evaluation by scientifically defending the dossier and clarifying the questions raised by the evaluators. Those questions were relayed to UNESCO-ICQHS and then its answers were transferred to ICOMOS through the Iranian Organization for Cultural Heritage. Finally WHC put the Persian Qanat dossier on the agenda of the 40th World Heritage Conference in Istanbul in order to be discussed and decided. At this conference 21 countries like Portugal, Kuwait, Turkey, Poland, Korea, Lebanon, etc had the right to vote, and they eventually decided on the dossier that they had already read through. This dossier met the approval of the member states with almost 100 percent of their votes and was announced as a world heritage.
This dossier pertained to 11 Iranian qanats as follows: