Tamil Nadu’s ‘encounters’ with artificial rain-making over the last 50 years

The Delhi government’s attempt to bring rain through cloud cultivation trials on October 23 and 29 has revived memories of similar operations carried out in Tamil Nadu in the last 50 years.

As in the last case, this practice was met with a modest response. The main difference between the current and past experiments is that while the Southern state desperately needed water to meet its drinking and agricultural needs, Delhi tried its luck with experiments to solve its pollution problem.

In January 1970, P. Koteswaram, Director General (DG) of the India Meteorological Department (IMD) (the post was then called Director General of Observatories), gave the first hint of experiments in making artificial rain that he would discuss with the Tamil Nadu government. Koteswaram, who was the first Indian to receive the Padma Bhushan (1975) and was elected Vice-President of the World Meteorological Organization between 1971 and 1975, cited the successful trials carried out in the Delhi, Agra and Jaipur regions in the previous 10 years by sowing seeds in clouds with salt injected from generators on the ground.

In a previous report Hindu In a letter dated August 18, 1968, the Union Ministry of Food and Agriculture, in consultation with the Council of Scientific and Industrial Research and the IMD, said it had prepared a five-year plan for conducting experiments on an intensive scale using aircraft in a suitable area. The experiments showed an increase in rainfall of around 20% in targeted areas, including Munnar (Kerala) and Tiruchi (TN), the report said.

Since the early 1970s were not kind to Tamil Nadu in terms of rainfall, the government showed great interest in the concept of artificial rain. The Indian Institute of Tropical Meteorology (IITM) conducted trials in and around Tiruvallur for three months from July 1973. Koteswaram, however, went on record as saying that in view of the “insufficient number of observations and some practical difficulties”, no definitive conclusion could be drawn that the rain occurring was due to cloud seeding, this newspaper reported on May 11, 1974.

Meanwhile, the Union government, on the orders of the Tamil Nadu government, had approached a Canadian firm in Mumbai to undertake a project to bring rain from monsoon clouds over Chennai and the Nilgiris. Giving details of this daily issue on April 30, 1975, the then Tamil Nadu Chief Secretary P. Sabananayagam pegged the estimated cost of the project at ₹ 1 crore, including foreign exchange component of ₹ 80 lakh.

About two months later, news emerged that artificial experiments would soon begin on the catchment areas of Chennai’s water bodies and the hydel fields of the Nilgiris district. The operation will begin after July 12 and continue until mid-November. It was stated that the three-person American team, consisting of a ground engineer, a pilot and a meteorologist, “will detect rain-bearing clouds with the help of radar equipment on the ground, fly over the clouds, plant chemical seeds in them and bring rain to the catchment areas.” Hindu He added that on July 8, 1975, the Americans conducted similar operations in their own country and in Africa. The project cost has been reduced to ₹ 12 lakh, including ₹ 10 lakh in foreign currency allowed by the Union government.

After the operations started, the basin regions received rainfall. For example, Poondi recorded 3.7 cm on July 21. While K. Chockalingam, the then Special Secretary of the State Agriculture Department, said that the area between Poondi and Red Hills also received rain, he was cautious about the one-to-one relationship between experiments and rainfall. After the first leg of the operations was completed on July 29, engineer member of the American team, Fred Clarke, claimed that approximately 20% more rainfall had occurred due to the seeding. Chockalingam stated that later there was some entry into Satyamurti Sagar in Poondi.

In an interaction with journalists in Pune a week later, IMD Director General YP Rao did not confirm claims that “the experiment of making artificial rain was successful immediately after a single flight into the clouds”. Writing an editorial, HinduOn August 13, 1975, he stated that “in his (Rao’s) opinion, such an instantaneous assessment is not possible and scientific testing should be carried out over a considerable period of time before any decision regarding the experiment can be made.” [now Chennai] The experiment is primarily about providing aid in one way or another to a place suffering from water shortage.

Two weeks before the dismissal of his government in January 1976, the then Chief Minister M. Karunanidhi explained to journalists the failure of the northeast monsoon in the composite areas of Madurai, Ramanathapuram and Tirunelveli districts. The state government was considering approaching the American company for cloud seeding operations over the regions.

Again in the early 1980s, the drought spell hit the state, especially Madras and its surrounding areas. This time the regime was headed by MG Ramachandran and Chockalingam served as Principal Secretary. In July 1983, the operation was carried out by a four-man American team led by Thomas Henderson. “Moderate rainfall” was recorded by Poondi. The experiments continued until October and after completion, the State government said the exercise cost ₹ 26 lakh, according to a report by this newspaper dated November 18, 1983. Eight months later, government sanctioned ₹62 lakh for cloud seeding operations [which began in July 1984] above the city’s reservoirs. As the situation was dire, the authorities went so far as to employ the services of violin master Kunnakudi Vaidyanathan, who filled the air on the banks of the Red Hills tank with the melodies of Amritavarshini. [a raga said to have been composed by Muthuswami Dikshithar]I beg the rain gods to answer.

The state government’s purchase of an aircraft for this purpose in 1983 came under criticism from the Controller and Auditor General, whose report was tabled in Parliament in November 1987. On November 10, 1987, this newspaper reported, “The State Government not only failed to adopt the usual tender procedure but also paid a price much higher than the price suggested by Hindustan Aeronautics Limited (HAL), which inspects second-hand aircraft.” Six years later, another report stated that “the aircraft remained idle for some time due to lack of spare parts and had to be sent to HAL for compulsory maintenance amounting to around ₹ 13 lakh and eventually had to be destroyed.”

Trials were conducted in 1993, when Chennai was once again facing water scarcity. By then, however, a consensus had emerged among the scientific community that no region received more than 20% precipitation over and above normal. A decade later, then Prime Minister Jayalalithaa made a statement but the authorities did not translate her decision into action due to lack of “proper conditions”.

The addition of Krishna water and Veeranam tank as sources to the Chennai water supply and many sea water desalination plants have made the city’s water supply position much better than in the past, making cloud seeding operations not even on everyone’s mind as an option to overcome drinking water scarcity.

As the situation was dire, the authorities went so far as to employ the services of violin master Kunnakudi Vaidyanathan, who filled the air on the banks of the Red Hills tank with the melodies of Amritavarshini. [a raga said to have been composed by Muthuswami Dikshithar, a member of the Trinity of Carnatic music]I beg the rain gods to answer.

It was published – 05 November 2025 06:00 IST