The scorching heat in south interior Karnataka over the last few weeks and the spectre of hotter days ahead has raised concern over depleting water levels in the Krishnaraja Sagar (KRS) across the Cauvery river, which is the main source of drinking water for major cities and towns in the region.
The water level at the KRS on February 28 was 90.23 feet against the maximum reservoir level of 124.80 ft. This is the lowest since 2018 for the month of February. It is only three times — including the current year — that the reservoir level has been so low in the last 10 years, as per data shared by authorities.
Sources in the Cauvery Neeravari Nigam Limited (CNNL) told The Hindu that that gross storage in the reservoir, as on February 28, was 16.075 tmc ft against the gross storage capacity of 49.45 tmc ft while the reservoir level in 2023 on the same day (February 28) last year was 107.02 ft while the storage was 28.829 tmc ft.
The previous lowest for the same day (February 28) was in 2017 when the reservoir level had plummeted to 81.40 ft and the available storage for utilisation had dwindled to 11.417 tmc ft.
On February 28, 2018, the reservoir level was marginally lower than what it was on the same day this year. It 80.88 ft while the available storage was 15.866 tmc ft.
From 2019 to 2023, the water level in the reservoir as on February 28 always hovered above the 100 ft mark. The level was 105.57 ft in 2019, 111.62 ft in 2020, 108.95 ft in 2021, and 113.70 ft in 2022.
In 2016 on the same day, the water level hovered at 93.31 ft while it was 106.58 ft in 2015, and 105.43 ft in 2014. Except on four occasions including 2024, the water level in the reservoir was above the 100 ft mark during February with the highest being 113.70 ft in 2022.
Not withstanding the depleting levels, officials expressed confidence that they could stave off the water crisis till the end of May. Sources said the available water could last till then after which the inflow to the reservoirs are expected to rise due to the onset of South West monsoon in June. The cumulative drinking water requirements for the cities and towns in the Cauvery basin in Karnataka is pegged at around 3 tmc ft per month.
In case of nature playing truant and a delay in the onset of monsoon, the reservoirs upstream, mainly Hemavathi, can act as a buffer, and water could be released to KRS. This water could be channelised for drinking purpose.
There is 13.45 tmc ft of water in the Hemavathi reservoir as on February 28 against its gross storage capacity of 37.10 tmc ft. Harangi has 3.38 tmc ft against the storage capacity of 8.50 tmc ft while Kabini reservoir has 11.74 tmc ft against the storage capacity of 19.52 tmc ft.
The gross storage capacity of the four major reservoirs in the Cauvery basin in Karnataka is 114.57 tmc ft against which the cumulative storage as on February 28 was 44.65 tmc ft. The figure was 64.61 tmc ft on the same day in 2023.
