“Supply of water obtained from the Vaigai (river) is so precarious that even in good years the paddy crop barely covers 20,000 acres annually although the existing tanks and channels command have enough land and sufficient hydraulic capacity for irrigation of double the extent, if only sufficient supply of water is delivered at the moderate rate,” says the book History of Periyar Project , authored by A.T. Mackenzie, the then Executive Engineer, Madras Public Works Department, Periyar Dam Project.
The statement made prior to the existence of the Periyar and the Vaigai dams speaks of the dry condition of the erstwhile combined Madurai district.
It is in this context that Periyar dam, constructed by the British in 1895, assumes significance in its contribution to irrigation of vast tracts of agricultural lands in Madurai.
The water from Mullai and Periyar rivers in Kerala that was wastefully draining into the Arabian sea was intercepted by constructing the 1,200-foot-long Periyar dam.
“The west-flowing river water was diverted to the east by digging a tunnel for 5,887 feet,” said former PWD Executive Engineer C. Suthanthira Amalraj. The water was let into Vaigai river through Vairavanar and Suruliyar.
The facts that the 15-lakh population of Madurai city gets its drinking water and over 2.08 lakh acres of land, mostly in Madurai, is being irrigated even after 120 years justify the painstaking efforts made by British engineer Col. John Pennycuick in constructing the dam under a very unfriendly environment.
That the drought and famine recurring in Melur taluk prompted the British to construct the dam is revealed in the words of Mackenzie.
“Almost every alternate season is one of scarcity in this taluk, and when an exceptionally dry year occurs there is severe distress, and the population is thinned by death and migration,” it reads.
Stating that north-east rain used to be highly uncertain, the book said that agricultural operations were seldom rewarded with a good yield.
One of the progressive farmers of the district, R. Arulprakasam, said that the 1869 Census revealed that around 1.23 lakh people were missing in the district.
“It was not clear whether those people died or they migrated elsewhere due to drought and famine,” the farmer said.
“Never had Melur taluk realised a full yield in paddy cultivation prior to Periyar water irrigating the vast farm land,” he added.
The British had originally planned to bring water only to Tirumangalam and not to Melur taluk. But, later when they found that Melur had a cluster of around 1,000 tanks that could hold around three times the capacity of the Periyar dam, water was brought to Melur. One of the main reasons for diverting Periyar water to Melur was people were increasingly involved in robberies, said Mr. Arulprakasam.
“Even a Collector then had noted in his diary that Periyar water had addressed to a great extent the law and order problem of the region after the commissioning of the dam,” he said.
Throwing more light on the technical aspects, Mr. Amalraj said it was Periyar dam, the subsequent construction of Vaigai dam, and modernising the irrigation system made possible extension of farming activities to 10 times the total area of land that was under cultivation then, and also and assured irrigation.
While originally Periyar dam was designed to irrigate only 1.5 lakh acres, the PWD took up modernising the system by lining the Periyar Main Canal and its 12 branch canals.
Water that was saved by way of preventing loss through seepage was used to extend irrigation in Tirumangalam through the Tirumangalam Main Canal.
Similarly, a link canal was constructed along the left flank of Vaigai river between Vaigai dam and Peranai to stop seepage of water while flowing through the riverbed.
Besides irrigation, the Periyar dam was providing drinking water to Madurai city, Theni, Andipatti-Sedapatti, Dindigul and hundreds of local bodies that had their infiltration wells of their water projects on the Vaigai riverbed. It also helps generating 140 MW of power.
Periyar dam did not bring just water to Madurai, but the winds of social change that made more people, who were indulging in antisocial activities, jump into farming activities.
“This resulted in a cultural sea change too. One cannot find jallikattu so popular in the region anywhere except for Madurai, Sivaganga and Cumbum (that were benefited by the Periyar water),” Mr. Arulprakasam said.
Stating that increasing of the water level in the dam to 142 feet from 136 feet will add 1,548 mcft of water, he said it would give an additional three turns of irrigation.
“Whereas all these days we had been fighting for one additional turn to save crops during the fag end of the irrigation seasons, the additional water will give us (the farmers) all the peace,” he said.
The city can also claim an additional reservation in the Vaigai dam for its drinking water requirements. Thus Periyar dam remains a lifeline for Maduraiites.
