Explained: How Bhakra Dam managed recent heavy rainfallhttps://indianexpress.com/article/explained/explained-how-bhakra-dam-managed-recent-heavy-rainfall-5924233/

Explained: How Bhakra Dam managed recent heavy rainfall

Thousands of lives have been affected even as standing crop on over 1,00,000 acres of land has got submerged under over 4 feet (ft) of water.

The Bhakra Beas Management Board (BBMB), which manages the Bhakra Dam on Sutlej in Nangal, has been working hard to manage Sutlej’s flow and reduce the losses downstream. (Express photo)

Very heavy rain over just three days – August 17 to 19 – have resulted in the Sutlej river overflowing and wreaking havoc in around a dozen districts of Punjab. Thousands of lives have been affected even as standing crop on over 1,00,000 acres of land has got submerged under over 4 feet (ft) of water. The Bhakra Beas Management Board (BBMB), which manages the Bhakra Dam on Sutlej in Nangal, has been working hard to manage Sutlej’s flow and reduce the losses downstream.

What is the height of the Bhakhra dam?

The reservoir height is 1,690 feet but since 2010, the upper limit for water was fixed at 1,680 feet by the BBMB. Earlier, the dam could be filled up to 1,686 ft.

How did the latest rainfall affect the water level in Bhakra Dam?

Just the rainfall between August 17 and 19 raised the water level in the dam by over 7 ft. It was 1674.82 ft before the rainfall started on August 17. It went to 1679.33 ft on August 18, and then 1681.25 feet on August 19, which was 1.25 ft above the maximum allowed limit.

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What was the inflow and outflow of water from Bhakra between August 17 and 19?

The Bhakhra dam received around 4.87 lakh cusecs in these three days and it released 1.85 lakh cusecs in the same period. It received 96,102 cusecs, 3.11 lakh cusecs and 80,000 cusecs on August 17, 18, and 19, respectively. While outflow was 53,000 cusecs, 55,000 cusecs and 77,300 cusecs, on August 17, 18 and 19, respectively. Against the inflow, the outflow was just 37.9% despite the dam crossing its upper limit.

The dam gates were opened on August 16 after the water level crossed the 1,675 feet water level with the heavy rains forecast for the next three days.

Similarly, the Pong dam on Beas got around 5.50 lakh cusecs in these three days due to which the water level in the dam increased by 16 ft from 1,362 to 1,378 in these three days. But since its maximum permissible water level height is 1,390 ft, the BBMB stopped power generation at the Pong dam to avoid further flooding in Punjab.