Karnataka considers cloud seeding in Cauvery catchment to boost reservoir levels

The Karnataka State Government is considering a cloud-seeding programme in the Cauvery catchment area to boost precipitation and address below-normal rainfall. During a recent government review, officials decided to seek expert opinion before taking a final call on renewing the weather modification initiative, which impacts key reservoirs supplying water to Bengaluru.

The proposal resurfaced amid concerns over dwindling water reserves in the Krishna Raja Sagar (KRS), Kabini, Hemavathi, and Harangi reservoirs. While Bengaluru has recorded a 35 percent rainfall deficit since the onset of the southwest monsoon, and south interior Karnataka faces a 24 percent shortfall, the Bangalore Water Supply and Sewerage Board (BWSSB) stated the city is unlikely to face an immediate drinking water crisis.

BWSSB officials noted that the city's current supply of 1,900 million litres per day (MLD) of Cauvery water, combined with an additional capacity of 300 MLD and the commissioning of Cauvery Stage V, brings total water availability to 2,225 MLD. This provides a buffer for the next three to four months, even as inflows into the KRS reservoir have started improving.

Cloud seeding involves dispersing particles like hygroscopic salts or glaciogenic agents into moisture-bearing clouds using specially equipped aircraft to accelerate natural rain formation. The state previously conducted a cloud-seeding mission between July and October 2019, where two aircraft carried out 83 sorties across 28 districts.

During the 2019 operations, 1,340 flares were deployed, resulting in an estimated average rainfall enhancement of 2.95 mm, which translated into an additional 7.4 TMC of water. This was more than three times the 2.1 TMC estimated during the state's 2017 cloud-seeding programme.

Despite past successes, scientists and the Union Government remain divided on the technology. The Centre has previously informed Parliament that artificial rain cannot solve drought conditions, as it requires pre-existing clouds with sufficient moisture and cannot generate rain under clear skies.