Despite Iran’s longstanding reputation for sustainable water management, the country currently faces mounting water-related challenges caused by population growth, industrial development, urban sprawl, lifestyle changes, climate change, territorial conflicts, poor management, and insufficient public participation. Since past and present water-related challenges share similar origins and patterns, addressing the past is imperative. After gathering, contextualizing, verifying, clustering, coding, and corroborating sources, we conducted a historical study to examine the relationship between water and Iranians from prehistoric times to the Islamic Golden Age (1219 AD). According to the findings, in prehistoric Iran, drought, flooding, river course changes, and the absence of a central government severely impacted water development. Despite doubts about the qanat’s origin, archaeological investigations indicate in the proto-historical period, qanat systems existed in Iran and the Arabian Peninsula. In 550 BC, the Achaemenids initiated a fundamental transformation in Iran’s water history by building dams, qanats, and water canals under a centralized administration. After a slump during the Seleucids (312–63 BC) and the Parthians (247 BC–224 AD), Iranians practiced water governance reborn under the Sassanids (224–651 AD). The Sassanids, like the Achaemenids, formed a powerful statement of unity, cooperation, and support among people for implementing their major water-related plans after enhancing institutions, laws, and communications. Chaotic Iran, however, endured severe water-related weaknesses in the Late Sassanids. Throughout the Islamic Golden Age, Iranians successfully traded water knowledge with other nations. As seen today in Iran, the Iranians have been unable to thrive on their resources since the Mongol invasion due to weak water governance, political tensions, and poor public support. The water sectors face more severe challenges when ancient water systems are ignored, applied without enhancement, or blindly adopted from other nations. Therefore, before current problems worsen, it is essential to integrate traditional and modern water cultures, technology, and management techniques.