Karnataka’s Water Woes: Rain Deficit in July, Depleting Reservoirs, Tamil Nadu’s Cauvery Demand

Karnataka may be facing a shortfall in rains in July when compared to the same timeline last year, but the scientists at the India Meteorological Department are optimistic and predicted widespread rainfall across the state in the next 72 hours.

“This will bring down the deficit, which is presently at minus 18 percent,” said A Prasad from IMD, Bengaluru.

Prasad predicted that areas, including Bidar, Belagavi, Kalaburagi, Chikkamagaluru, Kodagu and Shivamogga districts are likely to see moderate to heavy showers in the coming week. He also predicted slightly above normal rainfall over coastal Karnataka, Ghat districts and North Interior Karnataka.

But the Cauvery river basin is facing a severe rain deficit, especially in the Kodagu district that has received very less rainfall. The Cauvery originates from Talacauvery in Kodgau district. “The deficit has drastically come down. If you see the situation, where the deficit was 65 to 70 percent for Karnataka as a whole; and you see it as of today, the current deficit is of minus 18 percent, which means that Karnataka has received around 70 percent,” he said.

Kodagu contributes to the Cauvery basin, but the shortfall has been a cause for concern. “Kodagu has not been receiving rainfall. It is the origin of the Cauvery river and has recorded rainfall that has fallen short by minus 55,” said the IMD scientist.

According to the MeT, coastal Karnataka has a deficit of minus 12; north interior Karnataka is minus 7; and south interior Karnataka, including Bengaluru, Chikkamagaluru, Kodagu, Mandya, Mysuru among others, has a deficit of minus 29.

Cauvery water: To send, or not to send

Tamil Nadu chief minister MK Stalin has written to union jal shakti minister Gajendra Singh Shekhawat seeking immediate intervention, as he alleged that the Karnataka government had not been releasing the southernmost state’s share of Cauvery water despite intervention from the Cauvery Water Management Authority.

“In this critical scenario, the standing kuruvai (short-term paddy) crop can be saved only if Karnataka releases water immediately,” Stalin said in his letter.

State experts, however, said the rain and water deficit have also forced Karnataka to say that it will not be able to release water from the Cauvery to the neighbouring state. Karnataka is waiting for better rains before releasing the river water, said Karnataka agriculture minister N Cheluvarayaswamy.

According to the final directive of the Cauvery Water Disputes Tribunal (CWDT) and the Supreme Court, the Karnataka government is required to release 177.25 TMC of water to Tamil Nadu annually. But Karnataka is arguing that when it is already facing a major deficit of minus 21 this year, how will it be able to release the required quantity?

Tamil Nadu, in return, argued that Karnataka has released less amount of water instead of the prescribed quantity but the Karnataka government countered that by saying in times of excess rains, the state has released more than the prescribed quantity.

Last year, in the previous BJP regime, water resources minister Govind Karjol had said in a reply to a question raised by MLC Dinesh Gooligowda on water released to Tamil Nadu from the Cauvery: “In the four months between June to September, Karnataka has released 416.65 TMC to TN as against the allocation by the Cauvery Water Dispute Tribunal of 177.25 TMC of water to the riparian state.”

Karjol also said, as per the CWDT directive, Tamil Nadu is eligible for 101.08 TMC of water in the months between June and September, but four times more was released due to excess rainfall in 2022. A senior officer from the water resources department also said if excess water was not released from the swelling Cauvery basin, then dams in Karnataka would have burst or been breached.

Cheluvarayaswamy said if the rains, as predicted by the MeT, do not happen, the state government will have to declare affected districts as drought-hit and also try to introduce cloud seeding to improve the situation. In the background of this situation, water experts said agencies in Bengaluru and other cities must stress on rainwater harvesting and ensure that this kind of “dry state” does not occur.

Low water levels in major reservoirs

Depleting levels of various dams and water reservoirs in Karnataka is also a cause for concern. The levels were already low ahead of the monsoon but with the state staring at a rain deficit, the situation does not seem to improve anytime soon.

For example, for the Krishna Raja Sagar reservoir, which is a lifeline for farmers in Mysuru and Mandya districts, the water level is at 90.1 feet and at 33 percent of its storage capacity as on July 21. The reservoir had almost reached its full depth and storage capacity of 124.8 feet and 49.45 TMC, respectively, this time last year. In May, its depth had fallen to 83.6 feet; if this drops below 74 feet, the water will not be released for irrigation but saved as drinking water.

The rain prediction in the next 24 hours for south interior Karnataka, where the water reservoir is located, does not look as promising with a forecast of very light to light rains.

Another major reservoir, Tungabhadra at Vijayanagara district, is at 13 percent of its storage capacity (105.79 TMC). While Harangi (in rain-starved Kodagu) and Kabini (Mysuru district) reservoirs are at 73 and 67 percent of their total capacity, the Hemavathi dam in Hassan district is at 48 percent.

According to data from the Karnataka State Natural Disaster Monitoring Centre (KSNDMC), the state has a gross storage capacity of 895.20 TMC if 14 major water reservoirs are taken into account. As on July 21, the capacity of 11 reservoirs stand below 50 percent. The water stands at 31 percent (277.73 TMC) of the total storage capacity of all 14 major reservoirs; this capacity stood at 73.5 percent (655.88 TMC) this time last year.

IMD predicts heavy rains over coastal Karnataka

The IMD on Friday predicted light rains in Bengaluru with heavy rains over coastal Karnataka districts in the next 24 hours. It said thunderstorms with lightning are likely at isolated places over the state.

According to the IMD’s rainfall forecast, BBMP area (Greater Bengaluru metropolitan region), is likely to receive ‘isolated very light to light rains’. The maximum and minimum temperatures are likely to be around 29 degrees Celsius and 21 degrees Celsius, respectively.

The rainfall forecast on Friday showed that the state is likely to receive ‘widespread moderate to heavy rains’ over coastal Karnataka districts; ‘scattered to widespread very light to moderate rains with isolated heavy rains’ over Malnad districts; ‘scattered to widespread very light to moderate rains with isolated heavy rains’ over northern interior districts; and ‘isolated to scattered very light to light rains’ over southern interior districts.

In south interior Karnataka, the IMD predicted ‘isolated to scattered very light to light rains’ over Davanagere, Chitradurga, Tumakuru, Ramanagara, Bengaluru Urban, Bengaluru Rural and Mysuru districts; and dry weather will likely prevail over remaining places in the region, it said.

In north interior Karnataka, ‘widespread light to moderate rains with isolated heavy rains’ are likely over Belagavi district; ‘scattered to widespread very light to moderate rains’ are likely over Bidar, Kalaburagi, Yadgir and Dharwad districts; and ‘scattered to widespread very light to light rains’ have been predicted over remaining districts of the region.

In Malnad district, the IMD forecast ‘scattered to widespread very light to moderate rains with isolated heavy rains’ over Shivamogga, Hassan, Chikkamagaluru and Kodagu districts, whereas it said coastal Karnataka is likely to receive ‘widespread moderate to heavy rains’ over Udupi, Uttara Kannada and Dakshina Kannada districts.