The City District Government of Karachi (CDGK) signed an agreement last week with a Norwegian company, Aqualyng, to build a desalination plant on a 100-acre site near Hawkesbay to supply 25 million gallons a day of potable water to the city. The plant, which is being set up on a build-own-operate basis, will cost an estimated $200 million and will be completed in December 2009.

The funding for the plant is being arranged by the Norwegian company, while the land for the project has been allocated by the Sindh government. The Norwegian company will also set up a thermal power plant at its own cost to supply electricity to the desalination plant. The plant will be operated by Aqualyng Pakistan (Pvt) Limited, a subsidiary of the Norwegian company.

The agreement was signed by the Karachi Water and Sewerage Board’s managing director, Ghulam Arif, and Aqualyng Pakistan’s CEO, Sheikh Umar Farooq. Under a memorandum of understanding signed earlier on April 28, the proposed desalination plant was to be set up in Korangi to meet the needs of the Korangi Industrial Area. But after carrying out a study of the region, the Norwegian company decided to locate the plant at Hawkesbay.

In the first phase, the plant will produce 25 million gallons a day of potable water, which will be supplied to hundreds of factories and the general population in the city’s Sindh Industrial Trading Estate area through an 18-kilometre pipeline costing an estimated $10 million. In the second phase, the plant’s capacity will be boosted to 50 million gallons a day, making it one of the biggest desalination plants in the world.

Karachi’s chronic water-deficiency problem stems from the fact that the city has long been caught in the nutcracker of a burgeoning population, on the one hand, and limits on the amount of water the city can draw from the River Indus at Kotri Barrage on the other. To compound the problem, supplies from the Hub Dam reservoir – the only other source of bulk water supply to the city – are subject to fluctuation, depending on the amount of rainfall in any given year. Prolonged periods of drought in the dam’s catchment area, such as those seen a few years ago, can reduce aggregate supplies to the city from the Hub reservoir by as much as 50 million gallons a day or more.

Currently, Karachi gets a maximum of 650 million gallons a day of water from the Indus and Hub sources. Based on the city’s current estimated population of 16 million, the present total water supply translates into a water availability of about 40 gallons per person per day, or slightly more than half the figure of 70 gallons per person per day recommended by the United Nations as the minimum quantity needed for urban communities in developing countries.

Fuelled partly by an indigenous increase in population and partly by migration from other parts of the country, Karachi’s population is increasing by an estimated 4.5 to 4.8 per cent a year, as against the current national population growth rate of 2 per cent. To sustain this growing population, Karachi needs an additional 200 million gallons a day of water over the next ten years. But it cannot draw any more water from the Indus where downstream flows have been dropping for years because of less snowfall in the mountains due to global warming, and higher off-takes of water by Punjab from upstream reservoirs in the Indus basin river system for irrigation and other needs.

Water disputes between Punjab and Sindh have become common, with Sindh accusing Punjab of "stealing" more than its fair share of Indus water and Punjab hotly denying the charge.

The barrage that India is building on the River Jhelum in occupied Kashmir, in contravention of the Indus Waters Treaty, is likely to further reduce downstream flows in the Indus, into which the Jhelum feeds. Talks between the two countries to resolve this issue have failed. India is also building a dam on the Neelum River (a tributary of the Jhelum) in an effort to preempt Pakistan’s plan to build a dam on the same river, which flows along the Line of Control. Talks to resolve this issue have also failed, and India continues to press ahead with the construction of the dam.

Over the past twenty years, low flows in the Indus downstream of the Kotri Barrage have resulted in severe damage to the river’s delta ecosystem, including its mangrove forests and fisheries. Drawing any more water from the Indus for Karachi would only aggravate the problems of the delta region and could lead to an environmental catastrophe. Yet Karachi has to have more water to meet its growing needs.

The question is where is this additional water to come from? It cannot come from the Hub Dam reservoir, which depends on rainfall for its supplies and is, for this reason, an unreliable source at best. Nor can it come from underground water sources because acquifers in the Karachi region contain only brackish water that is unfit for human consumption. Moreover, the brackish water available from such sources is limited and cannot meet Karachi’s growing industrial, commercial and domestic needs. Given all this, the answer to Karachi’s water problems would seem to lie in setting up large-scale desalination plants to convert seawater into safe potable water.

In this context, the Karachi Port Trust has done well to initiate the setting up of a desalination plant to supply 25 million gallons a day of potable water to the city. The estimated foreign exchange cost of the plant is $60 million. The feasibility study for the plant was financed by the United States Trade and Development Agency through a grant of $287,480. The study was carried out by California Environ-Management, Inc (CEM), an American project developer company.

The plant, which is being built on KPT land, will supply potable water to the Karachi Port Trust for its own needs and for ships visiting the port, as well as to the CDGK’s Karachi Water and Sewerage Board for industrial and domestic use. After CEM received a letter of intent from the KPT to proceed with the project, the company teamed up with Burns and McDonnell, a Missouri-based company, to provide engineering services and act as overall project manager.

In a related development, the Defence Housing Authority is setting up a desalination plant in Karachi with a capacity of 3 million gallons of water a day. The plant will also generate 56 megawatts of electricity. DHA has entered into a joint venture agreement with Siemens Pakistan Limited to build and operate the plant. Work on the project began in 2003 and is now nearing completion.

DHA COGEN, the newly established owner company, and Siemens will run the plant in collaboration with DHA. The plant will supply desalinated potable water to the DHA area. The water produced by the plant will be sold to the Clifton Cantonment Board, which performs the civic body functions in the DHA area. The excess electricity generated by the plant will be sold to the Karachi Electric Supply Corporation.

After the 50 MGD Hawkesbay desalination plant, the 25 MGD KPT plant and the 3 MGD DHA COGEN plant come on-stream, Karachi’s water supplies will be augmented by a total of 78 million gallons a day.

Water service providers throughout the world face the challenge of meeting growing demand. A number of approached may be considered. One approach is to improve water distribution systems’ operations in order to reduce unaccounted for water. This will result in augmenting water supplies by reducing losses from leaks, theft or other causes. Other alternatives include better supply source management, promotion of water conservation technologies, and the introduction of tariff structures that discourage excessive water use.

At some point, however, water utilities will require additional water supplies to meet growing demand from domestic, commercial and industrial consumers. In Karachi’s case that point was reached more than ten years ago underscoring the urgency of finding a solution to the problem.