Temple-tank and eri (tank) irrigation hydraulics
What it is
Across peninsular India, communities engineered cascades of artificial reservoirs, the South Indian eri, by embanking shallow valleys to capture monsoon runoff for irrigation, recharge and supply. Chola-era inscriptions record sophisticated sluices, surplus weirs and village committees that maintained the tanks and allocated water. In settlements the sacred temple-tank served ritual bathing while anchoring the wider hydraulic network that sustained agriculture and towns. The system shaped a distinctive tank-fed urban and agrarian landscape across much of the south.
Why it matters
Tank cascades were among the most extensive community-managed water systems in the pre-modern world, embedding hydraulic engineering and collective governance into settlement form. They demonstrate a landscape-scale, decentralised alternative to monumental state waterworks.
Plans it shaped
- Anuradhapura (c. 4th c. BCE)
- Sigiriya (c. 477 CE)
- Angkor (Khmer Empire) (c. 9th–13th c.)
- Srirangam (Temple Island City) (c. 10th–17th c.)
- Vijayanagara (Hampi) (c. 14th–16th c.)
- Madurai (Temple City) (c. 16th–17th c.)
- Varanasi Kashi Corridor Urban Plan (2019–)
- Ancient City of Polonnaruwa (c. 1056–1232 CE)
- Kanchipuram (Pallava Temple Capital) (c. 6th century)
- Gangaikonda Cholapuram (Chola Imperial Capital) (c. 1025)
- Warangal (Kakatiya Circular Capital) (c. 13th c.)
- Chidambaram (Nataraja Temple-Town) (c. 10th–13th c.)