Through an examination of irrigation in eighteenth-century Ottoman Fayyoum, this paper analyzes how Egyptian peasants and Ottoman bureaucrats negotiated, managed, and used water. Water in the agriculturally rich countryside of Fayyoum—the most productive region of Ottoman Egypt outside the Nile Valley and Delta—was both extremely limited and clearly fundamental to the cultivation of foodstuffs for various cities and towns in Egypt itself and for the wider Ottoman polity of which it was an inextricable part. Fayyoum’s entire supply of fresh water during the Ottoman period came from a single canal branching off of the Nile and, thus, regulating this canal proved of the gravest political, economic, and ecological importance for both the Ottoman bureaucracy of Egypt and for Fayyoum’s peasant population. The single largest and most important irrigation feature on this canal was the Dam of al-Gharaq. Relying mainly on Ottoman imperial orders sent from Istanbul to Egypt about this dam, I show how the accumulation of silt behind the dam and the threat of its collapse structured the relationship between Fayyoum and the Ottoman Empire. For example, peasants in Fayyoum were able to petition the Ottoman state and to leverage its power and resources to fix this dam when it was in need of repair. And similarly the Ottoman state diverted resources from various regions of the Empire (wood from Anatolia and rope from Cairo for example) to repair this dam. Furthermore, my reliance on Ottoman imperial orders sent from Istanbul to Egypt is meant to suggest how Egyptian and Ottoman historians can use Ottoman archival materials to narrate the history of rural Egypt. The case of water in Fayyoum is a particularly good example of the utility of these documents since the court records of Beni Suef (the administrative subprovince to which Fayyoum belonged) are not extant. By combining an environmental history of water in Fayyoum with a discussion of Ottoman imperial practice in a provincial setting, this paper will be of interest to Middle East environmental historians and Egyptian and Ottoman historians alike.