David Hayes takes a look at how work is commencing on Tajikistan’s Pamir hydro power project
Work has started on the Pamir private hydroelectric power project in the Republic of Tajikistan that will bring much needed electricity supplies to the largely rural communities in the Gorno Badakshan Autonomous Oblast. Situated in the heart of the Pamir mountains, the region is one of the poorest and most remote areas in the world with most of the region’s 250,000 rural population occupied in subsistence agriculture and animal husbandry.
Hydroelectricity is the main economically viable energy source in the region where 77% of the population is estimated to live below the poverty line. Although subsidised coal and diesel oil were trucked into the region at great expense during the Soviet era, the availability of coal and diesel ended immediately that Tajikistan achieved independence and real market economics came into play. One consequence is that most schools and hospitals are closed in January and February, the coldest months of the year. Households now rely largely on biomass including cattle dung as the main energy sources for heating and cooking.
Pamir power project is being undertaken by Pamir Energy Corporation (PamirEnergy), which is 70% owned by the Aga Khan Fund for Economic Development and 30% by the World Bank’s private finance division, the International Finance Corporation (IFC). Since 1991 the Aga Khan Fund has used World Bank finance to build several mini hydro power schemes in Tajikistan and was involved in the construction of the existing 14MW Pamir I hydro power plant which is installed with two 7MW turbine generating sets and used American USAID development finance.
Pamir power project involves the take over and operation of all existing power facilities in Gorno Badakshan Autonomous Oblast by PamirEnergy under a 25 year concession agreement. Until recently all power plants, transmission and distribution facilities were owned and operated by a regional agency of the national power utility, Barki Tajik. However, the agency has allowed the generation and grid system to fall into an advanced state of decay causing power supplies to become unreliable and prone to disruption.
As a result IFC and the Aga Khan Fund proposed that the government permit the establishment of a 25 year concession for PamirEnergy to run the region‚s electricity service and implement the new power development investment programme. This will involve completing Pamir I station to its original design capacity of 28MW from its present 14MW installed generating capacity along with construction of a regulating structure at Lake Yashilkul. In addition other facilities including several mini-hydro power stations, substations, transmission and distribution lines will rehabilitated and upgraded.
The Aga Khan Fund is providing US$7.5M towards the total US$25M project costs while the IFC is providing US$7.5M consisting partly of equity and partly as debt finance. The World Bank‚s International Development Authority (IDA) soft loan window is lending the balance of US$10M to the government of Tajikistan.
All power generation facilities involved in Pamir dam are run of the river hydro power plants while the rehabilitation of power transmission and distribution lines will occur in existing sites so that no new land acquisition is required. As the power project environmental assessment has shown, the scheme is expected to have a limited number of environmental and social impacts which can be avoided or mitigated by following generally recognised performance standards, guidelines and project design criteria.
The completion of Pamir I near Khorog, the administrative capital of Gorno Badakshan Autonomous Oblast, forms the central focus of the project. Two additional 7MW turbine generator sets will be installed to raise the total installed capacity to 28MW. At the same time a regulating structure will be completed at Lake Yashilkul that is the source of the Gunt river which powers the Pamir I power plant. This will allow the release of additional water during the winter months to ensure that sufficient river flow is available for power generation at the time of highest electricity demand in the depths of Tajikistan’s bitterly cold winter.
Making an impact
The diversion of water to drive the expanded Pamir I power plant is not expected to have any impact on the river Gunt as a minimum ecological flow will be maintained in the river between the Pamir I intake and tailrace structures. All diverted water is returned from the power plant after use. Consequently the project has been designed to have no impact on the river’s downstream use though there will be some changes in the annual pattern of river flow.
Most significant potential impacts identified are expected to occur during the project’s construction phase when the level of Lake Yashilkul will be reduced by up to 2m and operation of Pamir power house will be interrupted for the inspection and rehabilitation of the tunnel.
The Pamir I environmental impact study forecasts that the following impacts may occur as a result of environmental changes during the construction phase. The fish population of the lake may reduce temporarily as the area of spawning grounds and aquatic vegetation may be reduced. In addition a temporary depletion of flood plain vegetation that provides grazing and fodder for livestock living around the edge of the lake may occur. Further temporary interruptions of the already unreliable power supply are expected.
Construction of Pamir I was originally planned in 1986 when Tajikistan was one of the Soviet Central Asian Republics, prior to the break up of the former Soviet Union. The project design has already been amended since the Aga Khan fund originally approached IFC for projecting finance support in 1998.
IFC commissioned technical consultant electrowatt-Ekono (EWE) to critically assess the original Soviet-era environmental impact assessment. The remit of the environmental review of the original project assessment focused on three points areas – the overall environmental effects of the Pamir power plant project; the effect of the plant‚s operation on the Gunt and Pianj rivers; and the quality of the previous Soviet era environmental assessment of the study.
The eventual assessment of IFC’s and EWE’s environmental specialists was that the original project design would result in unacceptable adverse environmental and social impacts including a permanent lowering of the level of Lake Yashilkul. As a result IFC asked EWE to revise the project design to reduce or completely eliminate the unwanted impacts. Public consultation was carried out in the project area to assess public reaction to the project, its environmental impacts, as well as the possibility of large increases in electricity tariffs.
Tajikistan’s Ministry of Environment is responsible for all environmental protection activities in the country. The ministry’s procedure is to issue a construction permit once it is satisfied that no environmental harm will arise from a project or that all measures to mitigate any potential harm have been taken. The current procedure follows the environmental impact assessment (EIA) procedure in place during the Soviet period. The original EIA for Pamir I was made in conformity with national regulations, which it has been established did not satisfy all requirements for IFC or IDA at the time.
In fact, Tajikistan has yet to adopt stringent and coherent regulations for EIA including definitions for project types requiring an iea, general procedures and responsibilities including those of the project proponent, general structure and content of EIAs, procedures for public involvement and other regulations. The United Nations Development Programme has prepared a programme to assist the government in strengthening the Environment Ministry’s institutional capability to carry out EIA studies when needed.
As a condition of financing the Pamir project the IFC and IDA required that PamirEnergy comply with applicable World Bank Group social and environmental safeguard policies in the construction and operation of the project‚s facilities. Various World Bank Group policies and guidelines were found to be applicable to this project including guidelines to protect natural habitats and ensure dam safety, along with environmental, health and safety guidelines for electric power transmission and distribution.
Pamir dam is located in the Gunt river valley, one of the rivers originating on the high plateau and draining into the Pianj river. Khorog, the administrative capital, lies at the confluence of the Gunt with the Pianj at an elevation of 2075m. Lake Yashilkul, from where the Gunt originates, is situated at the edge of the high plateau at an elevation of 3720m.
The climate is an extremely continental mountain climate. Temperatures in the region are characterised by very marked daily and seasonal fluctuations. The average temperature in Khorog is 23.7ºC in August and drops to minus 6.3ºC in January.
The region is rather dry with most precipitation falling as snow between November to April. The climate affects river flow. Winter river flow is very low while summer discharge is high, increased by water from melting snow.
The IEA study review carried out prior to the Pamir project being approved considered likely environmental and social impacts during the construction phase and eventual operational phase and mitigation efforts that are required. Monitoring will be required during the construction and operational phases and will be carried out by various government and non-government agencies.
To reduce costs for draining the construction pit for the regulation structure at the outlet of Lake Yashilkul, the level of the lake will be reduce by 2m during the two summers required for construction. This will increase river flow during the period of implementation, which will then reduce during the following spring and summer as water is retained to increase the lake level to its historic level.
Lowering the lake level in summer could affect groundwater levels in two floodplains adjacent to the lake, which also will be lowered. This could affect hay production for cattle feed in nearby areas during the construction period. PamirEnergy has agreed to compensate farmers affected either by supplying hay from other sources or with cash.
Once construction is completed and the lake returns to its historic level, potential negative effects on vegetation should cease. The operational monitoring programme will ensure this is the case.
Drawing down the lake could also affect fish stocks by reducing waterborne organisms on which fish feed and by reducing spawning grounds and interfering with fish reproduction which normally occurs in June. Monitoring of the lake’s fish population will be carried out during both the construction phase and later when hydro generation begins to detect any impact on fisheries.
Water pollution is another possibility during construction from fuels and other liquids at the project site and from vehicles employed in construction. Contractors as a condition of engagement will be required to ensure their workers follow strict pollution control guidelines which will be monitored during construction.
Once commercial operation begins an average annual draw down of 6m is expected to drive the power house turbines. The lake water level will be replenished by retaining water flow into the lake each spring and summer while maximum discharge will be in winter.
Although the Gunt river flows will change they will still correspond to their normal seasonal patterns. To avoid interfering with the fish spawning period, PamirEnergy hydrology engineers are expected to opt for a quick rise in the lake level as early as possible once the heavy peak winter generation load period has passed. This regime would operate in parallel with recommendations made for maintaining the floodplain vegetation which also requires the lake level to return to normal as fast as possible to avoid any reduction in vegetation growth due to the prolonged lowering of floodplain groundwater level.
At Khorog, the river Gunt flows into the Pianj river, which forms the border between Tajikistan and Afghanistan. The volume of water used for hydro generation is small compared to the flow volume of the Pianj river into which the Gunt flows and will have no significant impact on the Pianj flow.
Meanwhile, in conducting the initial project feasibility study, PamirEnergy also looked at alternative energy options that exist for Gorno Badakshan Autonomous Oblast. Transports costs for fossil fuels such as coal and diesel, used previously, are too high to be affordable while biomass including wood is too scarce to be an option.
Renewables such as solar power also are too expensive while wind speeds are low in winter, ruling wind energy out. Animal dung, already an important fuel, is fully utilized and, anyway, burning dung deprives farmers of their most important fertiliser.
Hydro power offers the best prospect to increase electricity output and the Pamir I project remains the most important scheme for the moment. Considerable potential exists for other mini and micro hydro schemes to be built though these tend to freeze in winter when power is most needed.