The 67-year-old Hirakud Dam, the world’s longest earthen dam, requires a comprehensive overhaul to address structural concerns and enhance capacity, according to a senior official.

Sudhir Kumar Sahu, additional chief engineer, Hirakud Dam Circle, has said that while the dam’s overall strength remains good, superficial cracks and cavities have been identified upstream of the reservoir.

“We are maintaining the dam properly and the Central Soil and Material Research Station and Central Water and Power Research Station have given good reports. Its strength is very good, but there are some superficial cracks and cavities upstream of the reservoir,” Sahu said.

The Hirakud dam is built across the Mahanadi, about 12km upstream of Sambalpur town in Odisha.

Located 6km from NH6, the dam is accessible from the Hirakud railway station and the Jharsuguda airport.

The 25.4-km-long dam, which creates Asia’s largest artificial lake spanning 743sqkm, was completed in 1957 as India’s first multipurpose project after Independence.

Construction began in 1948 after the foundation stone was laid in 1946 by the then governor, Sir Hawthorne Lewis. Then Prime Minister Jawaharlal Nehru laid the first batch of concrete in 1948 and the project was inaugurated on January 13, 1957.

Currently, the dam serves multiple purposes, including flood control, irrigation, power generation, and industrial and domestic water supply.

Sahu said the identified structural issues were being addressed through periodic treatment. “We have one package for underwater treatment under DRIP 3 and one additional spillway will be constructed,” he said.

The Central Water Commission has recommended building an additional spillway to handle increased water release capacity. While the current spillway can manage 15 lakh cusec, the new facility will help handle Probable Maximum Flood of 24.6 lakh cusec.

“CWC has told us to build another spillway, additional spillway. It is under process and MoU will be signed with the CWC,” the official said.

Regarding funding, Sahu explained that routine maintenance costs are borne by the state government while major schemes like spillway construction, underwater treatment and lining are funded by the Centre.

Despite good monsoon this year with increased water flow in rivers, there has been no flooding in downstream areas.