Mysuru: Despite Karnataka receiving 8 per cent excess pre-monsoon rainfall between March and May, several districts in the South Interior Karnataka (SIK) and Malnad regions, including key Cauvery catchment areas, have recorded significant rainfall deficits. The shortfall has raised concerns over water storage levels in major reservoirs even as the southwest monsoon is set to commence in June.
The India Meteorological Department (IMD) had earlier predicted above-normal pre-monsoon rainfall. However, the distribution of rainfall remained uneven, with southern districts receiving considerably less precipitation than normal.
South Interior Karnataka records 18 per cent deficit
South Interior Karnataka received an average rainfall of 107.8 mm during the pre-monsoon period against the normal rainfall of 131.1 mm, resulting in an overall deficit of 18 per cent.
The rainfall shortfall was particularly pronounced in the Cauvery basin districts, which depend heavily on seasonal rains for reservoir inflows, agriculture and drinking water supply.
Officials are closely monitoring monsoon developments as rainfall during the coming months will be crucial for replenishing water storage in reservoirs across the region.
Mysuru district faces severe rainfall shortage
Mysuru district recorded one of the sharpest rainfall deficits in the state during the pre-monsoon season. The district received only 93.3 mm of rainfall against the normal average of 190.4 mm, registering a deficit of 51 per cent.
Several taluks reported substantial rainfall shortages. H D Kote and Hunsur recorded deficits of 55 per cent each, while K R Nagar registered a 63 per cent shortfall.
Mysuru and Nanjangud taluks received 51 per cent less rainfall than normal. Periyapatna recorded a 45 per cent deficit, T Narasipura 56 per cent, Saraguru 37 per cent and Saligrama 57 per cent.
The significant reduction in rainfall has increased concerns among farmers and water resource managers regarding agricultural activities and reservoir inflows during the coming months.
Deficit rainfall in neighbouring districts
Other districts in the Mysuru region also experienced below-normal rainfall during the pre-monsoon season.
Chamarajanagar district recorded a deficit of 24 per cent, receiving 141.5 mm of rainfall against a normal average of 186.2 mm.
Mandya district reported a 33 per cent deficit, recording 101.8 mm of rainfall compared to the normal 152.9 mm.
The reduced rainfall across these districts is significant because they form part of the broader Cauvery river basin, which supports irrigation, drinking water supply and hydropower generation.
Malnad region also records shortfall
The Malnad region, known for its high rainfall, also experienced below-normal precipitation. Overall, the region recorded an 18 per cent rainfall deficit during the pre-monsoon period.
Hassan district received 105.5 mm of rainfall against the normal 155 mm, resulting in a 32 per cent deficit.
Kodagu district, which plays a critical role in the Cauvery catchment area, recorded a 45 per cent deficit. The district received only 68.7 mm of rainfall against the normal average of 126 mm.
The lower-than-normal rainfall in Kodagu has raised concerns about reservoir inflows and water availability later in the year.
Cauvery basin reservoirs hold less water
Water storage levels in major reservoirs across the Cauvery basin are significantly lower than those recorded during the same period last year.
As of Friday, the four major reservoirs in the basin collectively held 33.93 tmcft of water, representing about 30 per cent of their combined gross storage capacity of 114.57 tmcft.
The Krishnaraja Sagar (KRS) reservoir contained 11.38 tmcft of water against its full capacity of 49.45 tmcft. Kabini reservoir held 4.78 tmcft against a capacity of 19.52 tmcft.
Hemavathi reservoir stored 14.79 tmcft against its capacity of 37.10 tmcft, while Harangi reservoir contained 2.97 tmcft compared to its full capacity of 8.50 tmcft.
By comparison, on May 29 last year, the four reservoirs collectively held 63.12 tmcft of water, nearly 50 per cent more than current levels.
Drinking water supply remains secure
Despite the lower storage levels, officials have assured that there is no immediate concern regarding drinking water availability.
Authorities stated that the KRS reservoir currently has sufficient water to meet the drinking water requirements of Mysuru and Bengaluru until the end of June. The two cities together require approximately 2 tmcft of water per month for drinking purposes.
With the southwest monsoon expected to begin in June, officials are hopeful that sustained rainfall will improve reservoir storage and ease concerns over water availability in the coming months.