Which is the oldest existing surki mortar dam?
An anicut (a kind of small barrage) known as the Grand Anicut was constructed across Cauvery River by the kings of Chola dynasty some 2,000 years ago, mainly to provide irrigation to large areas in Thanjavur district. With some minor changes, the Grand anicut is still in use and is one of the oldest in-use irrigation structures in the world that have been successfully serving their purposes; this one meeting the requirements of Cauvery delta area in Tamil Nadu. The Grand Anicut is located downstream of Mettur reservoir. The irrigation demand from the anicut is 9,670 Mm3.