Baglihar Dam cleared by neutral expert
The overall design of the Baglihar dam being built by India on the Chenab as a run-of-river plant has been upheld by Prof. Raymond Lafitte, the Neutral Expert (NE) appointed by the World Bank to consider Pakistan’s objections to the Baglihar project, in his decision delivered today in Berne to the representatives of India and Pakistan.
The NE has emphasized the need to incorporate state of the art technology for projects built under the Indus Waters Treaty for reasons of safety and optimum utilization of the waters. He declares that “the general rules of treaty interpretation allow him to have recourse to rules of science and technology and the state of the art practices, in his assessment of the concept and design of the Baglihar Dam and Hydro Electric Plant”.
The decision of the NE recognizes India’s right to utilize the waters of the Western Rivers more effectively, within the ambit of the Treaty, for power generation.
This is the first time since the signing of the Indus Waters Treaty 1960 that a Neutral Expert has been appointed. Pakistan’s request made on 15th January, 2005 raised a number of Points of Difference for Expert Determination in respect of the design of the Project on the basis that certain features of the design did not conform to criteria specified in the Treaty. Pakistan contended, inter alia, that conditions at the Baglihar site did not require a gated spillway; that the spillway gates were not at the highest level; Indian calculations of the design flood and the height of the dam (Freeboard) were excessive; India’s calculation of the required Pondage of 37.5 MCM was also too high as the correct Pondage should be 6.22 MCM; and that the level of intakes for the Power Plant were not at the highest level as required by the Treaty.
After consulting the Governments of India and Pakistan, the World Bank appointed Mr. Raymond Lafitte, Professor at the Federal Institute of Technology of Lausanne, Switzerland as the Neutral Expert (NE) on 10th May, 2005.
During the 18 months period after his appointment, the NE held 5 meetings – in Paris, Geneva, London, Paris & Washington and also visited the Baglihar site and its hydraulic model at Roorkee. The Parties made written and oral submissions during the course of the Expert Determination.
The NE after a detailed analysis of a data base of about 13000 dams from the International Commission on Large Dams (ICOLD)’s World Register of Dams to analyse the type of spillway, gated or ungated, and a historical review of construction of large orifice outlets as well as a consideration of ICOLD guidelines, held that the site conditions at Baglihar require a gated spillway, and also held that in view of the high flood discharges and heavy silt loads, India’s design of gated spillways – both chute (surface) spillway and sluice spillways, as well as the number, size and location of their gates for the Baglihar dam complies with the design criteria set out in Annexure D of the Indus Waters Treaty.
This important element in the NE’s Determination will deeply influence all future interpretations of the Indus Waters Treaty. The NE has observed that the present day state of scientific and technical knowledge with advances in technology in dam design, not known or developed in 1960, can and should be utilized in dealing with problems such as those posed by heavy sediment which shorten the effective life of a plant. He is of the view that the reference in the Treaty to conceptual notions such as the need to ensure “satisfactory construction and operation”, “sound and economical design” and “customary and accepted practice of design” clearly not only permit but require use of latest technology. The NE has adopted the principle of effective interpretation which gives full effect to the rights and obligations provided by the Treaty, taking into account its object and purpose set out in the Preamble which is “attaining the most complete and satisfactory utilization of the waters of the Indus System of rivers”.
The NE accepts and regards as prudent India’s calculation of the design flood of 16,500 cumec (as against Pakistan’s figure of 14,900 cumec) in view of the uncertainties of flood analysis, possibilities of climate change etc.
The NE observes that the designer of a spillway is not only faced with the problem of flood control but also with that of sediment control and cites the “ICOLD” to note that the state of the art is today that “Bottom outlets may be used for under sluicing of floods, emptying of reservoirs, sluicing of sediments and preventing sediment from entering intakes etc.”
Accordingly, India’s design of sluice spillway at Baglihar with five outlets is regarded as appropriate and permissible under the Treaty for sediment control of the reservoir and evacuation of a large part of the design flood and being in conformity with the international practice and the state of the art. This decision will help India to deal more effectively with the problems of sedimentation in its future projects as the NE has confirmed India’s design of large bottom outlets (sluice spillway) as the most important technique to be employed in managing the high volumes of sediment which characterise the Himalayan Rivers. Incidentally, this had been an element of strenuous objection and India, in the course of the Expert Determination, constantly maintained that India’s design to deal with sedimentation problems by modern methods does not in any way interfere with the flow of waters of the Chenab River into Pakistan as required by the Treaty.
Based on the guidelines of ICOLD, the NE considers that the freeboard could be reduced by 1.5 metres. In this context, it is to be noted that India, in the spirit of good neighbourly relations, had offered possible reduction of freeboard to Pakistan even before the process of Expert Determination had started.
According to the NE, the first objective of “Pondage” is to regulate the flow of the river to meet the consumer demand. He considers that “Pondage” volume should be calculated taking into account only the variations in the load thus confirming the methodology adopted by India for calculation of Pondage. He disagrees with Pakistan’s method of determination of “Pondage” i.e. with the objective of operating the plant at constant power and regulating the fluctuations in the river flow. The NE has recognized the uncertainties in projecting future load variations. He has arrived at a slightly lower value of 32.56 Million Cubic Metre (MCM) of maximum permissible “Pondage” as against India’s design of 37.50 MCM. The NE has arrived at the lower value as he adopted a daily pattern of power generation which is slightly different from that adopted by India. As a result, there will be a minor change in the schedule of peak power generation. However, the number of hours of power generation per week would remain at about 49 hours as designed by India. According to Pakistan’s calculations, the maximum “Pondage” allowed was 6.22 MCM.
Another Point of Difference raised by Pakistan was regarding the elevation of Intakes for the Turbines for the Plant. The Treaty requires these to be located at the highest level, consistent with satisfactory and economical construction and operation of the Plant and with customary and accepted practice of design for the designated range of the Plant’s operation. Pakistan had suggested that provision of anti-vortex devices could raise the intake levels by about 7 metres from that designed by India. According to the NE, the normal practice is to go in for an appropriate arrangement of the intake structure. In particular cases where this is not possible for technical or economic reasons, then recourse could be taken to anti-vortex devices. The NE has also observed that the intakes should be so located as to avoid asymmetrical flow of water towards them. From his application of well known semi-empirical formulae, the NE considers that it is necessary to raise the power intakes by 2 metres and an additional 1 metre to allow for the slight reduction in “Pondage”. While the Indian designers of the project do not agree with the NE’s approach, as it reduces the water seal by 2 metres, no difficulty is expected in incorporating this change in the design of the Baglihar Plant.
The three elements of design which require marginal changes, i.e. reductions in freeboard and Pondage and increase in the height of the Intakes, all arise from calculations and not from basic principles.
The NE’s Final Determination confirms that India’s design has been compliant with the basic principles of the Indus Waters Treaty.
The NE also says that the reservoir level can be drawn down to a level of 818 m asl for maintenance purposes during monsoon each year. This will enable sedimentation management and ensure the sustainability of the project.
SK/SH/SK
(Release ID :24730)