Bhakra Dam deflection exceeds design limit; safety review planned

The Bhakra Dam has recorded structural deflection beyond its permissible limit amid consistently high reservoir levels, prompting the authorities to seek an assessment by experts.

Technical observations show the dam recorded a maximum deflection of 1.17770 inches this year, compared to the designed static loading limit of 1.03 inches. Yesterday, the deflection was 1.04 inches.

BBMB Chairman Manoj Tripathi confirmed that the deflection exceeded the original permissible level. He said the Bhakra Beas Management Board (BBMB) was planning to engage international experts through the National Dam Safety Authority to examine the reasons behind it.

According to sources, the reservoir’s maximum storage level is 1,680 feet and the minimum is 1,462 feet. In recent years, however, the water level has not dropped below 1,550 feet, preventing the dam from fully returning to its equilibrium position. Engineers believe the prolonged high loading cycle has contributed to the increased deflection.

Officials are planning a controlled drawdown during the coming summer months, targeting a level between 1,490 and 1,510 feet. Engineers said lowering the reservoir level would reduce structural loading and allow elastic recovery. They said the move was precautionary and not due to any immediate threat.

The drawdown might also aid partial desilting. The reservoir has reportedly lost nearly 25 per cent of its original storage capacity due to silt deposition from the Sutlej and its tributaries.

BBMB engineers continue real-time monitoring of the deflection, seepage and stress. Officials reiterated that the dam was structurally safe.