Wapda chief eyes dam diversions' completion in three years.

Byline: Khaleeq Kiani

ISLAMABAD -- Amid the launch of the construction of Diamer-Bhasha dam, the government on Wednesday said the decision to build it as a 'roller compact concrete (RCC)' structure was based on 20-year intensive scrutiny of technical and geological reports and feasibility studies by an international panel of experts.

Speaking at a news conference, Wapda chairman retired Lt Gen Muzammil Hussain said the project was initially among a list of 8-10 major projects identified by a Canadian consultant in the early 1980s and the choice for RCC dam was based on pre-feasibility and feasibility studies of the time.

According to him, the World Bank, which had originally agreed to support the project, appointed an international panel of experts from the US, the UK, Canada, etc, in 1997-98 under a regime of evaluation and approved it be built on RCC technology instead of earthfill or rockfill dam in view of the local topography, rainfalls patterns, etc.

Decision to build Diamer-Bhasha as a 'roller compact concrete' structure based on intensive scrutiny of technical, geological reports

In 2002-04, another panel of experts engaged by Wapda/government of Pakistan and led by Australian dam experts also concluded that RCC dam was best suited for Diamer-Bhasha because of expected glacial lake outburst floods in the Indus region and the fear that resultant overtopping flows could damage earthfill and rockfill structures downstream and the RCC was found to be a safe technology.

Moreover, the RCC was also found suitable from economic viability standpoint as this allows low level outlets, spillways and water passages within the main structure. This is not possible for earthfill or rockfill dam for which separate space is required. This was once again confirmed by another panel of experts in 2007-08.

On top of that, Lehmayr of Germany prepared a detailed design of the dam supporting the RCC option, which was again confirmed by a panel of experts. As such, the whole process concluding the RCC dam spanned over a period of 20-25 years.

Not only this, all experts have concluded that all dams on the Indus cascade should be RCC structures, including Bunji, Dasu, Pattan and Thakot.

In reply to a question, the Wapda chairman said the entire Rs480 billion financing for the dam was not required at the outset nor Wapda intended to contract this financing to pay management fee and other charges and hence it would complete financing in a staggered manner.

He...