Reasons: Monsoon failure, forest loss, land conversions in Kodagu

Mysore/Mysuru: Krishna Raja Sagar (KRS) Dam, the lifeline of the people of Mandya and Mysuru districts, which also caters to the drinking water needs of towns and cities in Cauvery basin and Bengaluru, has recorded the lowest inflow in 20 years during the monsoon year of 2023 and 2024.

The KRS Dam in Srirangapatna Taluk of Mandya district, which used to have sufficient water for drinking and agricultural activities, faces an acute shortage due to monsoon failure, rampant deforestation and unbridled land conversion for commercial purposes in Kodagu and depleting groundwater levels due to urbanisation, blocking rainwater seepage into the ground.

As per the figures furnished by the authorities of the Karnataka State Natural Disaster Monitoring Centre (KSNDMC), in the monsoon year of 2023-2024 (till May 31, 2024), the KRS Dam recorded an inflow of 78 tmcft and an outflow of 73 tmcft, the lowest in 20 years.

Records show that in 2003, the Dam recorded an inflow of 66 tmcft and an outflow of 19.6 tmcft. After 2003, this is the first time such a low inflow has been recorded.

Notably, the monsoon year of 2022-2023 fetched an inflow of 324 tmcft to the KRS Dam, and it recorded an outflow of 334 tmcft, one of the highest outflows recorded in the reservoir.

In 2022, the KRS Dam filled up twice between June and July. The actual capacity of the KRS Dam is 49.45 tmcft. The Dam received an inflow of 100 tmcft from June 1, 2022, to July 28, 2022. An outflow of 76 tmcft was recorded then. From July 12 to July 19, 2022 (8 days), the KRS Dam saw an inflow of 50 tmcft and an outflow of 48 tmcft.

The same year, the KRS Dam received the highest inflow of 324 tmcft, the highest in 20 years, and in 2018, the dam received 244 tmcft. In 2007, it recorded an inflow of 235 tmcft. Apart from the lowest inflow in 2003 and 2004 (97 tmcft), the dam received a decent inflow from 2005 (193 tmcft) until 2012 when it plummeted to 86 tmcft and recorded 79 tmcft in 2016.

Rainfall data

Taking the rainfall data of 2023-2024 during the Southwest Monsoon, from June 1 to September 30, Kodagu received just 1,278 mm of rainfall against a normal rainfall of 2,188 mm, a 42 percent depreciation. Mysuru received 267 mm against a normal rainfall of 419 mm, a depreciation of 36 percent, and as such, there was an inflow of 54 tmcft to the KRS Dam.

During the Northeast Monsoon from Oct. 1 to Dec. 31, 2023, it rained 259 mm in Kodagu against a normal rainfall of 288 mm, a 10 percent depreciation. Mysuru received 215 mm against a normal rainfall of 214 mm.

Good rainfall in 2024

However, taking into account the cumulative rainfall from Jan. 1 to Mar. 1, 2024, in Kodagu it rained 19 mm against a normal rainfall of 8 mm, recording a 214 percent increase, while it rained 12 mm in Mysuru during the same period against a normal rainfall of 8 mm, thereby recording a 63 percent increase.

During the pre-monsoon rains from Mar. 1, 2024, to May 31, 2024, it rained 300 mm in Kodagu against a normal rainfall of 245 mm (23 percent increase) and in Mysuru, it rained 251 mm against a normal rainfall of 198 mm, recording a 27 percent increase.

Overall monsoon failure: KRS Dam Superintending Engineer

Mysuru, June 2 (AG&BCT)- Speaking to Star of Mysore on the record 20-year low inflow, Superintending Engineer of KRS Dam Raghuram said that there has been an overall monsoon failure, leading to depleted inflows.

“Whatever it rains in the catchment areas of Kodagu, it is first used for agricultural purposes in the Mysuru and Mandya regions, and only then does it flow into the KRS Dam. We hope that this coming monsoon will bring good rainfall,” he said.