Are older dams and extremely heavy rains posing disaster threats?

Late on the night of August 10, 2024, at 12.03 am, the 19th crest gate of the Tungabhadra Dam in Karnataka’s Hospet gave way, raising alarm among lakhs of people in Karnataka and downstream Andhra Pradesh due to the imminent risk of flooding. Standing tall on the mighty Tungabhadra River, this 71-year-old dam serves as a lifeline for the region, flowing through both states.

The gate malfunction intensified concerns about the structural integrity of the dam as pressure from the reservoir water mounted. In response, all the gates were opened to release nearly one lakh cusecs of water, putting the northern districts of Karnataka and Andhra Pradesh’s Kurnool and Nandyal on high alert for possible flooding.

Inaugurated in 1953, the Tungabhadra Dam now faces renewed questions about its safety. The Karnataka cabinet announced the formation of a panel of experts to assess the condition of all dams in the state and provide recommendations on their safety.

Simultaneously, following the deadly Wayanad landslides in Kerala, worries surrounding the 130-year-old Mullaperiyar Dam have resurfaced. Built on the Periyar River in Kerala’s Idukki district, this dam is operated by the Tamil Nadu government for irrigation and power generation purposes. The safety of the Mullaperiyar Dam has been a contentious issue between Kerala and Tamil Nadu for over 35 years, especially following the 2018 Kerala floods, which saw the dam reach its maximum storage capacity. Adding to the concern is its location in a seismically active region.

The July 30, 2024, landslides in Wayanad have only heightened public fear, with many questioning whether the Mullaperiyar Dam is resilient enough to withstand sudden surges of water, particularly during heavy rains or cloudbursts.

As for the Tungabhadra Dam, repair work is expected to take a week but cannot commence until 60-65 per cent of the reservoir water has been discharged. This has left farmers upstream anxious about disruptions to their irrigation supply, while those downstream remain fearful of the flooding that could be triggered by the release of excessive water.