Small dams, big gains
Though a water-rich country, Pakistan is currently amongst the most water-stressed nations of the world, as its huge water resources remain under-developed. It is estimated that half of the country’s irrigation water is wasted due to poorly managed irrigation system and inadequate water infrastructure. In this context, construction of small storage dams can play a key role in promotion of agriculture, placing maximum area under cultivation, and thus bringing in a “green revolution” within a short span of time.
Developing small dams had never been the priority of successive governments. Since 1996, there had been no significant addition to small dams though a number of schemes were planned. The successive governments failed to focus on small dams’ construction, in spite of much scope in all the provinces. Though considerable experience in planning, design and construction of small dams is available locally since the 60s, it has not been utilised effectively. In every province, Small Dams Organisation continues to function, with supporting technical staff as an arm of irrigation department.
But the planners’ focus has always been on developing large and mega water projects, which are too costly and require long lead-time, bear negative impacts on large-scale population dislocation, other social and environmental concerns and have political dimensions too. These projects, costing multi-million dollars and requiring at least 10 to 12 years for completion, often run into snags and are delayed. The cost of two options may be visualised from the fact that 12 small dams in the Potohar region were completed in 1996 at a cost of $35.4 million, whereas Diamer-Basha dam is estimated to cost $8.5 billion.
Construction of large dams, which is feasible only in far-flung and isolated areas, faces communication and logistic problems and limitations of availability of labour. The development of infrastructure for large dams is consequently an expensive proposition, besides being totally dependent on foreign sources for dam construction.
Thus, local community-based small dams provide a simple, cheaper, reliable and manageable solution to water storage issues. Typical examples are cited of four small dams, Rawal, Simli, Misriot and Tanaza, which meet effectively water requirements of Rawalpindi, Islamabad and surrounding areas.
Nevertheless, small dams are not an alternative to large dams and mega multi-purpose water projects and can be considered of supplementary or complimentary nature. However, small dams are equally important to store and conserve water for increasing irrigation and drinking water sources and improving socio-economic conditions of the area. Also, small dams may not result in sustainable development of agriculture, in contrast to large dams, but its impact on groundwater development is positive.
Pakistan has constructed in all 58 small dams so far. According to reliable estimates, it has the potential to build another 750 small dams to meet water requirements of growing local and regional population. The trend in favour of small dams is being pursued in the developing countries. Sri Lanka has constructed some 12,000 small dams and Nepal more than 2,000. In India, which is considered a leading dam builder, 19,134 small dams have been developed and 52 small dams would shortly be constructed on Chenab and other rivers originating from Kashmir.
Punjab has constructed 32 small dams and the NWFP 15 small dams. Feasibility studies for constructing a large number of small dams in the country have confirmed economic viability, whereas studies are being undertaken for many others. Hundreds of potential sites for developing small dams countrywide include 20 small dams in the NWFP.
Plans are under way to construct another 20 small dams in Balochistan where many other potential sites have been identified. But no physical work has been initiated on any of these schemes as yet. Similarly, schemes for constructing another six small dams in the capital territory, for which economic viability was confirmed, have been shelved recently by the Capital Development Authority.
A special feature of small dams, where reasonable water head is available, is the generation of hydroelectric power, almost as a by-product. Small power stations can be established at such locations, based on proven technology, to generate electricity at the least cost and with low operation and maintenance charges. In present times, most of the dams are hydropower dams. These power stations will cater to the electrification of remote areas without any requirement to be connected with national grid.
Such small power stations of cumulative capacity of 242 MW are already in operation countrywide. Water and Power Development Authority (Wapda) operates eight small hydropower plants at Dargai, Jabban, Rasul, Chichoki Mallian, Shadiwal, Nandipur, Kurram Garhi and Renala. There are about 300 small hydropower stations in the Northern Areas generating 94 MW, providing electricity to the isolated network. There are another 11 small power stations in the NWFP generating five MW, which are operated in public and private sectors. Likewise, the government of the Azad Jammu and Kashmir successfully operates numerous hydropower stations including Jagran of 30 MW, Kundal Shahi, Leepa and Kathai, all of two MW capacity each.
According to studies conducted, potential exists to generate additional 2,166 MW hydroelectric power utilising proposed small dams. These schemes, which are power projects of capacity varying widely from 0.014 MW (14 KW) to 40 MW, can contribute effectively to the future power needs. Punjab plans to develop small low head projects on canals/barrages and streams/rivers. It has identified 306 sites on various canals and barrages, which can generate hydropower of cumulative capacity of 350 MW. However, no headway has been reported so far on its plans to set up small hydro-power plants under the Punjab Power Generation Policy announced about five years ago.
Likewise, five potential sites with low and medium head at canals in Sindh have the potential to generate 98 MW additionally. In the NWFP, 85 schemes of small hydro-power have been prepared of 570 MW cumulative capacities. Studies on 27 sites in the AJK verify potential of 230 MW power through small hydro-power projects. Northern Area, known for its rich water resources, has the potential of producing 885 MW at 139 identified sites for small dams.
Indeed, serious initiatives need to be taken by the government to implement small dams’ development programme, without further delay, utilising its own financial resources or seeking funds from the international donor agencies. The World Bank and the Asian Development Bank have already shown interest to finance small dams, as they did in the past.
(The contributor is currently on the Board of Directors of NESPAK)