Standards of engineering and hydrology require reliability of surplus flows for around ten months in a year to justify a new reservoir. Applying simple arithmetic on the author Zafar Mahmood’s own data negates the claim of surplus water and thus water for new storages is simply not available.

No irrigation and dam expert on earth would countenance occasional excessive flows as the basis for a large on-stream dam. In cases of extremely high flows like the 2010 floods, no dam would have been able to absorb a deluge of this magnitude. This has also been acknowledged by the author Mahmood.

Another important fact that has been ignored by him is the likely reduction of the inflow of Kabul River in the coming years. About 17 MAF water annually enters Pakistan through the Kabul River. It is estimated that the country may suffer approx 15-17 per cent drop in water supply from Afghanistan after construction of 13 dams on the Kabul River in Afghanistan.

The flow data monitored at Attock shows that Kabul River’s flow has sharply declined from 28 MAF in 1937-38 to 19 MAF in 2006-07. Future diversion in Afghanistan may eventually reduce the surplus for storage to a net deficit. In brief, the surplus water is not available in most of the recorded years and the available data does not corroborate the myth of wastage below Kotri. The future outlook is even grimmer in the wake of rapidly-changing climatic pattern and acrimonious relations with Afghanistan.

Wapda’s vagaries on the proposed two off-taking canals from the dam body is another thorny issue. Initial design of the dam clearly provided two canals on both sides of the dam. Although the World Bank experts did not endorse the proposition of stub tunnels on economic grounds, Wapda had desired for these canals to be part of the project. Another former chairman of Wapda, Shams-ul-Mulk, is a staunch supporter of these canals and has been publicly advocating for these canals to irrigate the southern parts of KP. Hence, the original design was not merely meant to store 6 MAF in the lake but also required almost the same amount of additional flows through each of the aforementioned two canals.

Zafar Mahmood mentions that the revised design presented to the CDWP/ECNEC in 1989 does not include these canals. However, the revised design has not yet been formally approved by the competent forums and the pro-dam lobbies in Wapda have not yet abandoned their plans for these canals. The author has also avoided discussing as to why Bhasha Dam has been put on the back-burner for several years.

Read also: The untold facts -- I

The feasibility of Bhasha Dam has already been completed and it was expected to be completed within seven years. As per schedule, this dam should have been commissioned by now. An inexplicably slouchy execution of the Bhasha Dam project seems a deliberate attempt to keep the Kalabagh Dam project alive.

Zafar Mahmood has discussed the impact of Kalabagh dam on the riverine area (kachho/sailaba) and the Indus delta in the episode 16 and 17 respectively. The author has indicated that KBD consultants had conducted a study on the need of irrigating the Kachho area. However, Sindh objected to the findings and demanded a fresh study which could not be conducted yet.

In the 1980s, Wapda commissioned a consortium of six consulting firms called Kalabagh Consultants (KBC) to study various aspects of the Kalabagh Dam. The consortium produced a very detailed report in 1983. The report "Kalabagh Dam Project Planning Report" spread over 13 volumes and scores of memorandums encompassed several aspects of the dam, but surprisingly the report did not include any volume on impacts of the dam on lower riparian areas such as the impact on Kachho area and the Indus delta. Who developed the terms of reference (ToRs) of the study and why such important dimensions were not included in the ToRs is an enigma.

Between Kashmore and Indus, the Kaccho area of Sindh is spread over more than two million acres. It is roughly divided into the present and the abandoned river channels (600,000 acres), forest lands (450,000 acres), roads, settlements and government structures (50,000 acres) and agriculture land (one million acres). Reliable estimates of the population in Kachho are not available, however a conservative count puts it close to one million.

Traditionally people in Kachho/sailaba area would abandon their abodes during the monsoon season and return after recession of flood. Leaving tons of nutrient rich silt and recharged aquifer, the floods used to be a boon for kachho community. People would just strew seed to have bumper harvests in the post-flood season. Sailaba area had been a breadbasket of Sindh. Seasonal inundation of kachho would herald rich seasonal harvest. Profusion of cereals, pulses and dairy and forest products would guarantee prosperous livelihood for the kachho community.

However, rampant damming and diversions of Indus during the recent decades have changed the flood regime entirely. Before Tarbela Dam, the Kachho area of Sindh received a flood of 300,000 cusecs almost every year and a flood of 500,000 cusecs for 77 per cent (three out of four) years. Tarbela Dam and other barrages have completely altered the flood pattern. Construction of any other dam will further curtail flows to the Kachho area. The situation is likely to aggravate during low flow years, potentially depriving hundreds of thousands of people of their livelihood in the Kachho area of Sindh.

Indus delta has become a case study for international research bodies to learn how upstream development unleashes ecological disaster in the downstream. The notion of 35 MAF wastage to sea, a handiwork of Wapda, has already been discussed at length. A misperception has been manufactured that 35 MAF water is flowing into the sea whereas Sindh needs only 8 MAF for its ecological balance in delta. What is dexterously masked under averages is the fact that between 1999-2000 and 2010-11 there were five years when flows below Kotri were not even 5 MAF. In year 2000-2001 and 2004-05, not even one MAF water crossed the gates of Kotri barrage.

No one can imagine the miseries of people living on both sides of Indus spread over 100 kilometres between Kotri barrage and sea during such lean years. If 35 MAF water is really being wasted to the sea, why is the Indus delta experiencing an unrelenting ecological havoc? This simple logic corroborates the claim that Indus delta needs much more than the current flows for its ecological sustenance. More than two million acres of land in coastal districts of Sindh have been devoured by the sea.

A few months ago, experts informed a Senate Standing Committee on Science and Technology that if urgent remedies were not employed, Thatta and Badin will be submerged by 2050 and Karachi by 2060. This ominous warning came from the experts of National Institute of Oceanography (NIO). The experts mentioned that for 300 days in a year, water did not flow to sea, which is a major causative factor behind incessant sea intrusion. This environmental catastrophe is completely obscured by illusory averages of excess flow to sea.

The Kalabagh Dam consultants’ marvel of 13 volumes did not find it worth studying as one of the most obvious impact of any large dam. Those busy in mourning the 35 MAF wastage to sea have never bothered to visit the delta. Millions of impoverished people are paying the price on a daily basis to sustain the prosperity enjoyed upstream.

While water bureaucracy takes pride in boasting dams and barrages for a massive increase in per acre yield, it easily turns blind eyes to the agonies endured by the delta dwellers. Coastal forest, fish stock, sources of livelihood and the whole ecosystem has been devastated in the coastal areas of Sindh.

Although Sindh had been clamouring on this injustice for decades, Wapda could not install any credible monitoring mechanism to observe the trend of sea intrusion. Simple data on a creeping boundary of tidal accretion, quality of subsoil water and salt content in the soil could easily establish scientific evidence if Wapda could not afford the commonly-available advanced technology. Premier environmental research and advocacy bodies like International Union for Conservation of Nature (IUCN) and Worldwide Fund for Nature (WWF) have conducted various research studies to prove that upstream diversion has caused irreversibly detrimental effects on the delta.

Kalabagh Dam has been scorned by three provinces and pressing for the project further would jeopardise a much-eroded national unity and inter-provincial harmony.

Concluded