Bengaluru/Mysuru: With the Cauvery water-sharing dispute raging, forecasts of below-normal rainfall in Aug have deepened furrows on both sides of the border and have strengthened Karnataka’s argument against releasing water to Tamil Nadu.July ended on a worrying note for Karnataka, with South Interior areas — which includes Bengaluru and most Cauvery basin districts — recording a 27% rainfall deficit, pushing the region into ‘deficient’ category in Indian Meteorological Department (IMD) parlance.Overall, the state recorded 17% rainfall deficit — which falls within IMD’s ‘normal’ range — but several areas were severely deficient, while North Interior Karnataka emerged as the only subdivision with a marginal 1% surplus.Key Cauvery basin districts, including Bengaluru Urban, Bengaluru Rural, Mandya, Hassan, Kolar, Chikkaballapur, Ballari and Tumakuru, witnessed large deficient rainfall in July, raising concerns over drinking water supply and irrigation.The outlook for Aug offers little comfort. IMD has forecast below-normal rainfall across most parts of the state, barring a few districts in Kalyana Karnataka. The El Niño effect, currently in a moderate phase, is likely to strengthen, increasing the likelihood of prolonged dry spells. “Seasonal rainfall is deficient for Karnataka as a whole (27%) with South Interior areas being 35% deficient. El Niño is expected to strengthen in the next two months,” said Latha Sridhar, scientist at IMD.Sporadic rainfall has reflected sharply in reservoir storage. Karnataka State Natural Disaster Monitoring Centre (KSNDMC) data shows the state’s 14 major reservoirs are only 52% full, with storage in the Cauvery basin at 57%, Krishna basin at 64%, and the Hydel basin at just 34% of their gross capacities.The contrast with last year is stark. Four major Cauvery reservoirs currently hold 65.3tmc, compared with 105.4tmc on the same day last year. Storage in the Krishna basin has declined to 269.8tmc from 344.9tmc, while hydel reservoirs have witnessed the sharpest fall, dropping to 110.6tmc from 244.8tmc a year ago.Despite the recent uptick in inflows, water resources department officials say the gains are insufficient to offset the cumulative rainfall deficit. Since the onset of the southwest monsoon on June 1, total inflows into Karnataka’s reservoirs reached 340.8tmc, including 10.6tmc into the Krishna basin, 2.8tmc into the hydel basin and 1.4tmc into the Cauvery basin on Friday alone.
