Abstract: the Archives that have survived intact to our day is a good indication that the Ottomans had an excellent system of administration established in almost all their government offices. It is well known that Mehmed II had established the Su Nezareti, the Department of Water, under the Director of Waterworks that was responsible for the administration of water issues. However, this does not mean that the Ottomans, who had inherited the Byzantine and Seljuqid lands along with their water conduits and aqueducts as well as some of their administration, did not have an administrative office to solve the water problems. In this article, based on the documents from Ottoman archives, I will concentrate on Ottoman system of administering and managing water conduits as well as the procedures followed in supplying water to the towns and cities. There is no doubt carrying water from springs and dams by way of water conduits and aqueducts into reservoirs and from there to the water tanks (maslak), chambers (maksem) and balances (su terazileri) from where the water is distributed to the mosques, medreses, hans, public baths, fountains and houses is a considerable task that can only be achieved through a well established administration. The Ottomans, as part of this system, built new water conduits and aqueducts as well as maintaining the old ones. The Department of Water, besides being responsible from inspecting and supervising such tasks as these, supplied men and material as well as found money, and insured that everything ran smoothly. It is a fact, based on the documents, that the Ottomans had the water conduits and aqueducts guarded, brought to justice those who were responsible for damage, made sure the water was distributed to the public equally, and had the waters analyzed regularly to ensure that it was hygienic and suitable for drinking