Environmental historians have judiciously questioned the usefulness of political periodization when historicizing processes of environmental change. Processes such as the silting of a dam or watershed degradation, we are reminded, are not dictated by the rise and fall of different regimes. But to what extent should we also consider environmental legacies distinct to specific national projects, such as those of the Pahlavi Dynasty (1925-79) and the Islamic Republic (1979-present). This paper will reflect on rupture and continuity—or perhaps more aptly, revolution and evolution—in modern Iran’s history of water resources policy. Hydraulic projects on both sides of the revolution were driven by material demands and political expediencies, but they were also informed by specific environmental imaginaries integral to the regime’s state-building. Mohammad Reza Pahlavi (r. 1941-79), aspiring to restore the supposed fertility of pre-Islamic Iran and consolidate state power on the margins, embarked on an aggressive campaign of dam building and agricultural modernization in the 1960s and 1970s. The campaign largely failed to improve agricultural output, triggering severe social and environmental repercussions. Upon replacing the Pahlavis, the Islamic Republic strove to undo the ancien régime’s environmental legacy and return water resources to the disenfranchised masses, legalizing unlicensed deep wells across the country. But as ideological commitment to “redistributive justice” met economic realities, the clerical regime adopted developmentalist policies, boasting a dam building record that put the Pahlavi planners to shame. The paper will explore these policies through their environmental consequences, representations in the public discourse, and implications for state-society relations.