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Resources: Do we need big dams
One of the most talked about issues in Pakistan has been the building of dams. We see a lot of people commenting on their merits and demerits. It has often been maintained that big dams have gone out of favour and the nation can easily meet its water and energy needs through small dams.
It is also said that the mighty Indus can be tapped in its upper reaches, especially near Skardu, resolving the problem of water and energy scarcity in the country. That the people coming up with such faulty arguments may not be qualified enough, however, has rarely been mentioned.
Before discussing whether or not big dams have gone out of favour, or if the alternatives on offer hold any water, it seems appropriate to state some facts. At present a little over 54.5 million acres of land is under cultivation in Pakistan (in all the provinces), while a chunk of 22.5 million acres is waiting to be tapped.
In addition to the need for bringing this huge acreage under cultivation, we see that tail-enders of various canals don’t get enough water. The drought-like conditions, as witnessed in recent years, have led to great shortfalls in production.
This is largely why we have had to import food grains. The drought, however, did have its positives in the shape of better drainage. That it has led to a reduction in the earlier proposed expenditure of Rs33 billion, under the National Drainage Programme, is another story and surely a recipe for disaster if the present climatic wet cycle stops short of expectations.
From these statistics, we can conclude that 7.5MAF to 10MAF of extra water needs to be made available firstly in order to cater to the depleted capacity (to the tune of 4.89MAF) in the existing mega-storages of Tarbela, Mangla and Chashma and secondly to irrigate at least a portion of the area not under currently cultivation.
The country’s per capita water availability has already reached the alarming figure of 1,126 cubic metres per person, while anything less than 1,000 cubic metres per person is considered as disastrous.
We also see that our country is fast approaching an energy crunch — up to 1,700MW by the year 2007. In case the present national growth continues at a medium level, this shortage of 1,700MW by 2007 is going to increase at least to 5,000MW by the year 2010.
The last time an effort was made to resolve the power crisis was in the early 1990s when several Independent Power Plants (IPPs) were set up. This had a debilitating effect on the economy, with the economy still being plagued by it. This can be gauged from the fact that Wapda had to pay 50 per cent of its total revenues to buy 33 per cent of its energy needs from the IPPs for the financial year 2004-05 alone.
As a consequence, whatever people say about the purported efficiency of the private entrepreneur or the good which the IPPs had done for the country, it is a fact that we have to come up with a new solution to bridge the gap in the supply and demand of power and to meet our future energy requirements.
This becomes even more important when we try to grapple with the issue of affordable power tariff rates and the fact that the same can only be taken care of if the hydel-thermal mix of power generation remains around a ratio of 70:30, as opposed to the current ratio of 35:65. International oil prices and their ramifications on countries like Pakistan also should be taken into consideration.
The idea of producing hydro-power through canal heads is not new. In addition to several small power plants that are in operation in the country since decades, Wapda has identified a total potential of about 700MW which may be generated at 500 different sites.
However, the maximum potential at any given site is not more than 5MW. On an average a small plant can only produce 1MW of electricity.
Connecting a number of small power plants to the national grid is another problem. Consequently, the total cost of numerous small plants, if built, will be much greater than that of a single power house running through a big dam.
From the above, it can be concluded that in order to irrigate the 54.5 million acres of land already under cultivation, to bring additional areas under cultivation, and to enhance our power generating capacity we need to better harness the available water resources. We have to devise an efficient system between now and 2010.
As economics play a vital role in all projects of importance, the most economical means should be adopted, otherwise we will not succeed in achieving our goals. This can only be done through the creation of mega-reservoirs.
This can happen only if we build large dams. Similarly, our capacity to generate power can only be increased efficiently through big dams, which lead to production of electricity as a bye-product at very low rates.
It also needs to be remembered that electricity usage in Pakistan depends upon many factors, including some cultural aberrations due to which we witness huge fluctuations in load during the course of a single day. This necessitates the enhancement of production capacity which can only be handled properly through appropriate additions to the existing number of hydel stations.
Implementation of conservation programmes to offset losses in the transportation and distribution of both water and power are sometimes put forth as a potential solution. Indeed, conservation is important and cannot be discounted, but on its own it cannot be deemed a viable option. Also, it can never do away with the need for big reservoirs. Actually, conservation and construction of new facilities need to move concurrently.
Two things, thus, are important — namely the need for an additional 7.5MAF to 10MAF of water and up to 5,000MW of power. How this can be achieved without the use of big dams is unclear.
Let’s see now if big dams have really gone out of favour throughout the world. Well, we see that internationally there is a clear divide between those who support big dams and those who don’t.
We see that people are against construction of dams in the North American continent and also in the once pro-dam areas like Brazil and its neighbours in South America.
Similar is the case for quite a few of the North European/Scandinavian countries. Delving a little deeper, we see that all these areas are energy surplus. Canada and Brazil stand out as good power producers, with tens of thousands of megawatts of spare generation capacity. The situation is such that up to 40,000MW of spare cheap hydel power in Canada is not allowed to be exported to the American Mid-West (which gets its power requirements transported from other nearby states at a much higher cost).
The North European/Scandinavian countries after having generously tapped hydel resources and also after using cheap local coal apparently have no use for further generation, especially when nuclear generation takes care of the needs of the energy-starved nations of Europe like France (which fulfils above 50 per cent of its needs through nuclear power plants). Similarly, these areas of the world also crop huge quantities of water and thus do not feel any need for new reservoirs.
On the other hand, we see that countries like China, Turkey, India, Iran and even an industrially advanced country like Japan are in the process of building as many as 707 dams, out of which 161 would be more than 200ft high, putting them in the “big dams” category.
Thus, for a country like Pakistan, solution lies in the construction of big dams one after the other. Otherwise, we would be heading towards an Ethiopia-like situation. Our growth will peter off and we may not even be able to meet the demand for food.
The writer is honorary treasurer of the IEEEP
Reservoir Sedimentation (Maf)
Reservoir
Gross Storage Capacity Gross Storage Loss
Original Year 2004 Year 2004 Year 2012 Year 2025
(Maf) (MAF) (MAF)
Tarbela 11.62 (1974) 8.36 (72%) 3.26 (28%) 4.17 (36%) 5.51 (47%)
Mangla 5.88 (1967) 4.64 (78%) 1.24 (22%) 1.72 (29%) 1.97 (34%)
Chashma 0.87 (1971) 0.48 (55%) 0.39 (45%) 0.48 (55%) 0.50 (57%)
Total 18.37 13.48 (73%) 4.89 (27%) 6.37 (35%) 7.98 (43%)
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