Major part of Tamil Nadu enjoys rainfall during winter season while summer remains dry. This requires irrigation to make up the deficiency of rainfall. Canal irrigation is popular in deltaic and coastal areas accounting for 29 per cent of the net cropped area.
1. Kaveri Delta Canals-The Kaveri delta has the oldest and the longest (6,400 km) irrigation canal system in the state. These canals taken off from the Grand Anicut (built in 1889) irrigates about 5.15 lakh hectares of land in Thanjavur and Tiruchchirappalli districts.
2. Mettur Canal System-these canals taken out from the Kaveri River (Mettur dam) provide irrigation to 1.8 lakh hectares of land in Salem and Coimbatore districts.
3. Lower Bhawani Project Canals-Bhawani Sagar reservoir has been constructed over the Bhawani River to irrigate 78.917 hectares of land in Coimbatore district.
4. Periyar Project Canals-a barrage has been built across the Periyar River and its water is transported to the Suruliyar River (tributary of the Vaigai River) through a 1737 m tunnel. This water is distributed through 432 km long canals to irrigate about 40,000 hectares of land in Madurai, and Ramanathapuram districts.
5. Katalai Canal-the Katalai High Level Canal irrigates 8,300 hectares of land in Thanjavur and Tiruchchirappalli districts.
6. Manimuthar Project Canals-The Manimuthar is a tributary of the Tamraparni river over which an earthen dam has been constructed. Canals taken out from this dam irrigate 41,694 hectares of land in Tirunelveli district.
7. Parambikulam-Aliyar Project Canals-this is a joint venture of Tamil Nadu and Kerala states under which 244 km long canals have been constructed to utilise the water from eight rivers to irrigate 97.13 thousand hectares of agricultural land.