River Cauvery, the lifeline of Tamil Nadu, is also an inspiration for writers and artistes. The sobriquet “Chola Naadu Sorudaithu” (Chola kingdom has food) came to composite Thanjavur district because of the “Annanadai” (food path) of Cauvery. Alongside its banks flourished our art and culture. It is because of Cauvery that the composite Thanjavur district earned the name granary of Tamil Nadu as well as cradle of our art and culture. Folk songs emanating from the paddy fields and classical songs and dance from temples are a simultaneous reality in composite Thanjavur district.
Cauvery, originating from Kodagu in Karnataka, used to flood the delta region in olden days. Farmers irrigated lands by opening the channels using their legs. Aged farmers recall the days when they would go to the fields in the morning and remove the soil blocking passage of water to their fields with their legs. Water would gush into the field. At the end of the season, they would reap a good crop. That was Cauvery delta of yesteryear. A new canal called Grand Anicut Canal was formed by engineers to utilise the surplus water stored when Mettur dam was conceived in 1925 and executed between 1925 and 1935. The canal was part of the Mettur project. It was thought, and engineers were quite right, in that more ayacut had to be brought under irrigation to make optimum use of the water stored in Mettur dam. The canal runs 148 km from the Grand Anicut and irrigates lakhs of acres of land in Thanjavur and Pudukottai districts. This area was called new delta, old delta being irrigated by the Cauvery and Vennar river systems. Yet another unique feature of the Grand Anicut canal is that it can take the quantity of water released at its head at Grand Anicut till the end.
Mention and description about Cauvery river and its environs is found in Silappathikaram, written by Ilango Adigal. Kannagi, walked alongside the Cauvery when she went to Madurai to seek justice. Other literature which speak about Cauvery are Pattinappaalai, Aganananooru, Purananooru, Manimekalai, Periyapuranam, Kamba Ramayanam, Raja Raja Cholan Ula, Kanthapuranam, Cauvery Puranam, Vinayakar Puranam, and Devaram of Thirugnanasanbandar. Poet Subramanya Bharathi in one of his songs speaks about the exchange of betel leaves of Cauvery basin to wheat products of the Ganges basin. (Gangai Nathipurathu Kothumai Pandam, Cauvery Vetrilaikku Maarukolvom)
The Grand Anicut was constructed to regulate flood and irrigation. If flood water was not carried into Coleroon river from Grand Anicut, the entire delta may be flooded. But even now in these years of scarcity, when skies open up the Coleroon (Kollidam) absorbs the excess water.
After a long battle to solve the river water dispute between Tamil Nadu and Karnataka, a finality has now come in the gazetting of final award of the Cauvery River Water Disputes Tribunal. One hundred and ninety two tmc of water should be released by Karnataka and a mechanism for getting this water has to be made by central Government like forming of Cauvery Monitoring Board and Water Regulation committees.
An unhealthy development of converting fertile land into housing plots is threatening to drastically change agriculture scenario in the delta region. A frustrated farmer is ready to sell his land. A greedy real estate trader is waiting to grab the opportunity.
Yet another major threat looms large over the delta. Beneath the surface level cultivable land which is enriched by the fertile soil (vandal) the rivers bring in, are the precious natural recourses like lignite, oil, and methane which oil companies and other industry are waiting to tap. When opened, delta may go the Neyveli way, it is said.
Although the Cauvery basin is yet to be declared a profitable area, the oil companies are continuing exploration with the hope of finding a huge reserve.
The spread of prawn farming in the region too emerged as a major threat to agriculture in the delta region. However, agitations by farmers and court cases brought in some regulation. All these threats have to be removed and if the scenic beauty of the delta is to be preserved.
Kamban captures it in his poem, Thandali Mayilgal Aaada, Thamarai Vilakkam Thanga, Kondalgal Muzhavinenga, Kuvalai Kan Vizhithu Nokka, Thendirai Ezhini Katta, Thembizhi Mahara Yaazhin Vandugal Inithu Paada (peacock will dance, lotuses will hang like lamps, clouds will play mridangam, Kuvalai flowers will blossom, gentle breeze wafting across, honey bees will hum like Yaazh, a musical instrument). “That is Marudham land,” concludes Kamban. Marudham is the paddy field and its surroundings.