Taunsa barrage is one of the important diversion structures, built across Indus River and its tributaries. The barrage experienced ripping of downstream floor and damages to friction blocks in year 1959 soon after it started operation in year 1958. Similar damages were reported and subsequently got repaired in years 1962, 1986, 1994, 1998 and 2003. Excessive retrogression and consequently the sweeping of hydraulic jump were noted as the main reasons for damages to floor and friction blocks. Irrigation and Power Department, Government of Punjab decided to rehabilitate and modernize Taunsa Barrage on emergency basis. A subsidiary was constructed downstream of the barrage to raise downstream water level; consequently to keep hydraulic jump over the glacis. The subsidiary weir location and crest level was fixed on the basis of numerical and physical model study. This research work discusses the hydraulic/structural deficiencies which consistently damaged downstream floor and impact/friction blocks at the Taunsa barrage. Furthermore the suitability of subsidiary weir as rehabilitation structure is also discussed.