Contrary to our current approachto water, as a colorless, odorless and tasteless liquid, Iranians were used to understand it as apurifier; the most precious substancewhich was dowry of their profit’s daughter, andthe resource of whole life on earth. The main aim of this article is to present an explanation for how the alteration of Iranian mentality on ‎‎water has led to the excessive water consumption today by illuminating the factors which have ‎‎affected this change.‎ In pursuit of this goal, the article proceeds in five steps. First, the theoretical ‎basis which the paper relies on is discussed by using the psychology of advertising and cultural studies ‎findings; As a prologue for the historical account, a brief outline of water supernal value among Iranians ‎before the modern era, through secondary written sources, is raised; Then urban water resources ‎management in Qajar Tehran is described by analyzing the data gained through historical maps and ‎documents besides memories, both in macro and micro levels of the city ‎‏ ‏to show the physical ‎organization of water resources and problems associated with the operation of water; after that, Iranian ‎mentality on water during Qajar period is explained based on historical evidence; and at the main ‎part, taking advantage of all the previous stages, it is discussed how the promotion of tap water has ‎led to the alteration of water concept and its value in the Iranian mind; Finally, according to previous steps, two categories of ‎strategies and tactics for the propagation of optimizing water use is proposed.‎