This year, Tamil Nadu will witness the centenary celebrations of M. Karunanidhi (1924-2018), one of its tall leaders and a prominent son of the soil from the Cauvery delta region. This year will also mark the centenary of a historical event concerning the river. In the age-old dispute between Tamil Nadu and Karnataka over the sharing of Cauvery water, the 1924 agreement, signed by the predecessors of the two southern States in February that year, is into the 100th year.
Though the final order of the Cauvery Water Disputes Tribunal, of February 2007, has superseded the agreement, one of the key effects of the agreement is the Mettur dam, which is going to be in focus for at least the next six months as it will be opened for irrigation on Monday (June 12).
The genesis of the dam dates to the proposal mooted in 1834 by Arthur Cotton (1803-99), a celebrated British engineer credited with having implemented irrigation projects that helped to avert famines and stimulated the economy of south India. Cotton had thought of damming the Cauvery to improve irrigation in the composite Thanjavur region. Later, many engineers pursued the idea. At one point of time, it appeared that the Bhavani, a tributary of the Cauvery, and not the main river, would be selected first. But there was no consensus among water experts.
In 1901, the then Inspector-General of Irrigation, Thomas Higham, after perusing reports on the proposed Bhavani and Cauvery reservoirs, preferred the proposal of having a dam across the Cauvery. Nine years later, Col. W.M. Ellis, chosen for drawing up a detailed scheme, submitted his report. Analysing his proposal, ‘History of Cauvery Mettur Project’, a 1987 publication of the Central Board of Irrigation and Power (CBIP), points out that Ellis, while selecting the dam site, “was able to secure” all the conditions that were essential for a dam of the size proposed, whereas “the sites proposed by earlier investigators all lacked one or more” of the essentials. This publication was based on a document authored by C.G. Barber in 1936 and revised by A. Mohanakrishnan in the 1980s.
When the Ellis scheme was under consideration of the British authorities, the Cauvery dispute assumed serious proportions between the then Madras and Mysore governments. An award by a Court of Arbitration in 1914 forced Ellis to revise his plan. In the meantime, the Madras government challenged the award, leading to negotiations between the two provinces. Eventually, the two had reached an understanding and signed the agreement on February 18, 1924. The pact covered, among others, the construction of Krishnaraja Sagar dam (in Karnataka) and Mettur dam (in Tamil Nadu).
It took a year for the government in the U.K. to clear the estimate for the project, and the cost was fixed at ₹6.12 crore, about ₹1 crore more than the Ellis’s scheme of 1910, records the CBIP publication.
On July 20, 1925, the then Governor, Viscount Goschen, formally inaugurated the work. The address presented to him, while recounting the history of the dam project, referred to the role played by C.P. Ramaswami Aiyar (1879-1966) in getting the 1924 agreement signed and the dam project commenced. Addressing the event, Aiyar, who was Law Member in the Executive Council handling subjects including irrigation and electricity, referred to apprehensions in certain quarters that the government would eventually hand over sources of water and power to “some syndicate” and asserted that the sources were the “property of people” and “ought to be conserved as their property and developed as such,” says a report of The Hindu on July 21, 1925.
In a sense, the delay in the commencement of the Mettur project was a blessing in disguise: on July 26, 1924, the Cauvery saw a flood of 4.56 lakh cubic feet per second (cusecs), whereas Ellis had provided for 2.5 lakh cusecs. The previous recorded was 2.07 lakh cusecs in 1896. Now, the dam, through spillways, can discharge 4.41 lakh cusecs.
‘A foremost expert’
The construction of the dam took nine years and the dam came into use on August 21, 1934. On the same day, The Hindu, in its editorial, identified Sir C.T. Mullings (who served as Consulting Chief Engineer and Engineer in Chief) as the foremost expert who had evolved the scheme and pointed out that his work had been recognised by the conferment of knighthood.
As part of the dam project, the Grand Anicut Canal System was created to serve 3.01 lakh acres of new area, followed by the Kattalai and Jedarpalayam bed regulators. Two more reservoirs — Bhavanisagar and Amaravathy — were built across the tributaries of the Cauvery in 1953 and 1957 respectively. There have been several other developments over the years.
The important benefits of the dam are stabilising irrigation, ensuring livelihood for lakhs of farmers and landless workers and contributing to food security. This is evident from the fact that paddy is grown in the Cauvery delta on at least 15 lakh acres through three cultivation seasons — Kuruvai, Samba and Thaladi — if the data since 1996 are any indication. Needless to say, Samba is the main season with a minimum of 10 lakh acres.