The dry-zone water-harvesting and management system in Sri Lanka is one of the oldest historically recorded systems in the world. A substantial number of ancient sources mention the management and governance structure of this system suggesting it was initiated in the 4th century BCE (Before Common Era) and abandoned in the middle of the 13th century CE (Common Era). In the 19th century CE, it was reused under the British colonial government. This research aims to identify the ancient water management and governance structure in the dry zone of Sri Lanka through a systematic analysis of ancient sources. Furthermore, colonial politics and interventions during reclamation have been critically analyzed. Information was captured from 222 text passages containing 560 different records. 201 of these text passages were captured from lithic inscriptions and 21 text passages originate from the chronicles. The spatial and temporal distribution of the records and the qualitative information they contain reflect the evolution of the water management and governance systems in Sri Lanka. Vast multitudes of small tanks were developed and managed by the local communities. Due to the sustainable management structure set up within society, the small tank systems have remained intact for more than two millennia.