Efficient management of water resources guarantees food security, environmental protection, and sustainable social and economic development of human societies. Hydraulic engineering plays a pivotal role in the optimal management of water resources for various uses, with the aim of regulating water flow, storage, and transportation. The present study aimed to investigate the architecture and practicality of Iranian hydraulic structures in the Sassanid era (case study: structures in the south and southwest of Iran), and the present study focused on hydraulic structures in the provinces of Khuzestan, Fars, and Bushehr.The research method in the present study is historical and the research method is descriptive and analytical. The information was collected based on library resources and field research, and after reviewing the resources and taking notes, the information was analyzed and written. The results of the present study show that during the Sasanian period, Iran witnessed a significant development in the construction of water structures, which indicates a deep understanding of water resources management and hydraulic engineering. These structures, including causeways, dams, and extensive networks of irrigation canals, played a vital role in the development of agriculture, the supply of drinking water, and the economic prosperity of various regions of the empire.