Chola Gangam Lake – A Ruined Symbol of Rajendra Chola’s Legacy
Context: To commemorate the birth anniversary of Rajendra Chola I on Aadi Thiruvathirai , the Tamil Nadu government has announced a ₹20 crore development plan for the historic Chola Gangam lake (Ponneri tank) near Gangaikondacholapuram.
The tank, constructed by Rajendra Chola I after his northern military campaign, is mentioned in the Tiruvalangadu Copper Plates. Rajendra Chola's birth anniversary has been officially celebrated since 2021.
About chola gangam lake:
Chola Gangam, also known as Ponneri Lake, is a 1,000-year-old reservoir near Brihadisvara Temple at Gangaikonda Cholapuram in Ariyalur district, Tamil Nadu. It was built by Rajendra Chola I to commemorate his victorious northern expedition and symbolically brought Ganga water to the South, as recorded in the Tiruvalangadu Copper Plates. Historian K.A. Nilakanta Sastri described it as a “liquid pillar of victory.”
Originally spread over 16 miles, the tank has now shrunk to 17 km and remains mostly dry, as the canals that once brought water from the Kollidam River have been abandoned. Once irrigating over 1,564 acres and supplying water to the Chola capital and palace, it now lies in neglect. The Trichinopoly Gazetteer (1855) praised its embankments, sluices, and massive capacity, calling it one of India’s largest reservoirs.
The tank’s elliptical bunds, made with laterite stones, and its sluices and sediment traps reflect advanced Chola water engineering. The structure allowed for sediment-rich silt to be deposited in paddy fields, enhancing soil fertility—managed through local tax collection (eri-ayam) and community maintenance (kudimaramathu).
The tank’s decline has caused groundwater depletion, disrupted bird migration routes, and destroyed a key drainage outlet for Veeranam Lake.
Kollidam river:
The Kollidam is a river in southeastern India. The Kollidam is the northern distributary of the Kaveri River as it flows through the delta of Thanjavur. It splits from the main branch of the Kaveri River at the island of Srirangam and flows eastward into the Bay of Bengal.
