According to Tungabhadra Dam authorities, water level in the reservoir was receding by 5 mm to 6 mm daily owing to evaporation.
DH File Photo
Kalaburagi: Soaring mercury levels across Karnataka – some parts of the state are already registering maximum temperatures of 40 degrees Celsius – are extracting a huge cost on water bodies such as lakes, agricultural ponds, and even irrigation canals, which are drying up at an alarming speed. Experts have attributed increasing evaporation levels to climate change, while depleted green cover has also resulted in the fog thinning out.
Narayanpur Dam Assistant Engineer Vijaykumar Arali said that the reservoir was losing up to 150 cusecs of water every day owing to evaporation.
Pointing out that this figure was only going to rise in April and May, Arali added, “Around one tmcft of water is likely to be lost due to evaporation by the start of the monsoon, according to our estimations. We are supplying water to meet both drinking water and irrigation requirements. We will not have to grapple with water scarcity as long as we supply water for irrigation only till March 23, in accordance with the directions of the Krishna Bhagya Jal Nigam Limited, but problems may arise if we continue to supply water for irrigation thereafter.”
Tungabhadra Dam engineer Raghavendra said that water level at the reservoir was receding by 5 mm to 6 mm daily owing to evaporation. “This will only increase over the next three months. Engineers at Narayanpur Dam informed us that, on average, 145 cusecs were lost to evaporation in February this year, as opposed to only 120 cusecs in the corresponding month in 2024,” said Raghavendra.
Underscoring the detrimental impact of climate change on the availability of water in North Karnataka, hydrogeologist Devaraj Reddy N J said, “Each square metre of the soil could extract up to 12 litres of water from a single night’s fog until 10 years ago. But this has come down by at least 50% now, pushing mercury levels higher, and resulting in loss of water to evaporation in water bodies. Rise in loss of water through evaporation by 5% is abnormal.”
Farmers storing up to one crore litres are likely to lose 20% of it to evaporation despite laying HDPE liner sheets, he added. “Owing to rise in temperatures in the past fortnight, farmers have removed plastic floating shade balls to check loss of water through evaporation,” Reddy added.
Lack of humidity and dry weather conditions in North and South Interior Karnataka are among the reasons why more water is lost through evaporation in these regions, said head of India Meteorological Department’s Bengaluru office Dr N Puviarasan.
“Moisture from the sea helps keep evaporation in check in the coastal region,” said Puviarasan.