BELAGAVI: Dams play a pivotal role in Karnataka’s economy, agriculture, water supply and generation of power. Given the state’s dependence on variable monsoons and its vulnerability to frequent droughts, dams are essential for sustainable water resource management.
As an agrarian state, Karnataka relies heavily on irrigation, with nearly 60 to 70 per cent of its agriculture dependent on water from dams. With Karnataka being a leader in hydropower generation in South India, its dams contribute significantly to the state’s renewable energy capacity.
But if not maintained well, dams can turn into ‘water bombs’, wiping out lives and an entire region. That’s an extreme scenario but cracks, cavities and wear and tear over the years should make one conscious and cautious about that possibility. Alarm bells rang recently when reports of cracks and cavities emerged in the 50-year-old Kabini dam in Mysuru district.
A crest gate of the Tungabhadra dam in Hospet collapsed last August. Experts have suggested replacement of all the 32 gates of this ageing dam.
The movement for clearance or decommissioning of unsafe dams has gained momentum, particularly in the West. According to experts, dams might collapse due to the degeneration of the structural material and failure to resist earthquake impact.
The hydrological safety of dams is a concern. Heavy rain due to cloudburst or glacial lake outburst due to climate change can lead to a sudden surge in water level. In October 2023, the Teesta dam in Sikkim was destroyed in a flash flood.
According to Mohan V Katarki, a senior advocate at the Supreme Court and an expert in Transboundary Water Law, dam safety is the legal responsibility of the owner of the dam, whether government or a private body. The law of tortious liability is absolute and, therefore, the owner of the dam cannot even plead it was an ‘act of god’ if the dam breaks and causes damage to people’s lives and properties downstream. Compensating lakhs of people will be unthinkable, says Katarki.
“Generally, dams in Karnataka are safe but continuous monitoring by experts and stakeholders is very important. The Dam Safety Act, 2021, enacted by Parliament is constitutionally doubtful since water is a state subject. Secondly, the Act does not give voice to stakeholders,’’ adds Katarki.
Dam safety review panels at the state and Central level inspect dams every year to take stock of the situation. “A pre-monsoon and post-monsoon review of every dam in the state is being done under the guidance of the chief engineer of the Water Resources department. Based on reports of the review panel, a report is submitted to the Central Water Commission, which decides what works have to be taken up to repair damages in the dams,” says D Basavaraj, chief engineer, Krishna Bhagya Jala Nigam Limited (KBJNL).
The Dam Safety Committee is monitoring damages in an attempt to initiate necessary repair works, according to sources. Water resources management experts say to ensure the dams’ continued effectiveness, it is imperative to invest in proper maintenance, adopt sustainable water-sharing policies and modernise infrastructure.
Multiple concerns at Harangi dam
Constructed in the 1970s, Harangi dam in Kodagu district was designed to support farmers across the Cauvery basin, while also ensuring regulated water flow to the Krishnaraja Sagar (KRS) dam in Mandya district.
The dam is confronting several environmental and man-made challenges. In 2018, the dam was filled with approximately 1.2tmcft (thousand million cubic feet) inflow of silt. The sedimentation continues to affect the reservoir’s storage capacity. Mismanagement of water release from the Harangi dam in 2018 was cited as a major contributing factor to devastating landslides in the Hattihole and Thanthipala regions.
Currently, projects amounting to Rs 130 crore are under way to bolster the reservoir’s resilience. Among these, Rs 50 crore has been allocated for the construction of a gabion wall intended to prevent further siltation. Additional measures include strengthening the catchment areas and initiating the long-overdue removal of the deposited silt.
“An estimated 1.2tmcft of silt has settled inside the reservoir. We are now taking steps to remove it,” said Puttaswamy, executive engineer of Harangi division.
Unauthorised stone mining has been reported within a one-kilometre aerial radius of the reservoir at Gondhibasavanahalli. Large tracts of land have been deforested to facilitate private stone extraction operations, raising alarm over potential structural risks to the reservoir.
“No action has been taken against illegal mining. This not only threatens the ecological balance but also endangers the very safety of the reservoir,” said Chandramohan, convener of the Cauvery Swachata Andolana. He also expressed concern over unregulated adventure tourism in the Harangi backwaters, where tourists reportedly enter the area without proper identity verification or safety measures.
As development efforts proceed, the dual challenge of ecological conservation and law enforcement remains essential to ensuring the sustainability and safety of the Harangi dam.
Almatti equipped with hydraulic gate system
Almatti dam is equipped with a state-of-the-art hydraulic gate system that ensures round-the-clock safety and smooth operations, said D Basavaraj, chief engineer of KBJNL, who oversees the maintenance of the dam. “Unlike the Tungabhadra dam, which has a traditional chain system, Almatti dam is the first in the state to feature a hydraulic gate system,” he said. The hydraulic gates are inspected twice a year and a check is carried out ahead of every monsoon.
A dedicated gate sub-division office, headed by an assistant executive engineer, oversees maintenance activities at Almatti. “The possibility of gate failure at Almatti is negligible. The construction of Almatti dam was completed in 1998, and the gates have been operational since 2002. Over the past 22 years, no issues have been reported,” he said.
Minor upgrades needed at Hidkal dam
The Raja Lakhamagouda (Hidkal) dam has passed its annual third-party inspection, with only minor upgrades recommended, according to Mahaveer Gani, superintendent engineer of Hidkal dam. Gani said the dam undergoes annual structural and functional assessments by independent agencies. The latest inspection was completed a month ago.
Built to a height of 62.48 metres, Hidkal dam is equipped with 10 vertical crest gates that help regulate downstream water flow. These systems remain vital to managing the region’s water resources, catering to both irrigation and drinking water needs for thousands across Belagavi and nearby districts.
Regular checks at Linganamakki dam
Shivamogga district has several dams, including Linganamakki, constructed across the Sharavathi, and others, including Bhadra and Tunga dams. Gerusoppa, Linganamakki, Mani and pick-up dams were constructed across the Sharavathi in Sagar and Hosanagar taluks.
HR Ramesh, Chief Engineer (Operations and Management), said, “Every year, we take up pre-monsoon and post-monsoon checks of all operations of the reservoir gates, both crest and radial. As of now, there are no issues pertaining to the operations of all crest and radial gates.”
(With inputs from: K Shiva Kumar in Mysuru, Firoz Rozindar in Vijayapura, Tushar A Majukar in Belagavi, Prajna GR in Kodagu, Kiran Balannanavar in Hosapete, Ramachandra V Gunari in Shivamogga, Divya Cutinho in Mangaluru and Prakash Samaga in Udupi)
