ISLAMABAD, Sept 28: In view of an increasing frequency and intensity of floods, the Punjab government has decided to take flood protection measures for 100 years, starting with capacity enhancement of Sulemanki and Trimmu barrages to let more waters pass through major structures with minimum loss.

A senior official of the ministry of water and power told that the provincial government had sought advisory support from the federal government to start rehabilitation and upgradation of the barrages which are more than eight decades old. The Asian Development Bank has already agreed to extend $900 million for the Punjab Irrigated Agriculture Investment Programme (PIAP).

The official said the provincial government had finalised the rehabilitation and upgradation model for the Sulemanki barrage, which allows passing of a total of 430,000 cusecs of water, including 332,000 cusecs discharge at high flood level with an additional capacity to pass 98,000 cusecs discharge downstream of the barrage.

Hydrological analysis suggests that a maximum discharge of 430,000 cusecs of water could hit the barrage in 100 years of extraordinary floods. The barrage height will be increased by 1.45 feet.

The sources said that consultants hired by the government in consultation with the ADB had also proposed operation of breaching sections to protect barrage structure in case of extreme floods, but it was turned down by the provincial government.

“In the given political and social circumstances, nobody will allow operation of breaching section,” the official said, adding that “even law-enforcement agencies were not able to operate the breaching section due to enormous political, social and media pressures during the 2010 floods”.

Built in 1927 on the river Sutlej, the barrage currently has a capacity to discharge only 325,000 cusecs of water, which has since then reduced to 301,000 cusecs. The structure has already outlived its life and had deteriorated over the years due to aging, which could be rehabilitated for another 100 years.

The official said that more than 50 army bunkers on the India-Pakistan border had weakened some of the bunds and hence the upgradation would also provide wetting channel to test its safety and strength before every flood season.

The total canal command area of all the three canals originating from Sulemanki is 2.5 million acres, which is 9.25 per cent of the total irrigated area of Punjab (27 million acres) and cover six districts of Punjab -- Bahawalpour, Bahawalnagur, Okara, Pakpattan, Vehari and Lodhran.

The existing capacity of Trimmu barrage is 607,769 cusecs against its design discharge of 645,000 cusecs. The 100-year flood estimates put a maximum flooding of 875,000 cusecs. An additional structure of 267,000 cusecs will be required to ensure protection against floods for over 100 years.

The advisory group on barrages, comprising federal and provincial authorities, is currently studying three options to enhance the Trimmu's capacity. These include additional 13 bays adjacent to the right abutment of barrage, provision of a bypass fuse plug with cross structure on Rangpur canal and provision of a bypass gated weir with crossing structure across the Tangpur canal.