Bulgarian-greek Cooperation For the Intergrated Water Management of The Mesta/Nestos Transboundary River Basin.

Bulgarian-greek Cooperation For the Intergrated Water Management of The Mesta/Nestos Transboundary River Basin.
ABSTRACT – The Mesta/Nestos River basin is one of the case studies of a FP5 European project “Iron Curtain” for development of a methodology and information basis for integrated regional planning and decision making support of sustainable regional development. Priority of the Mesta/Nestos River basin is the social and

economical development of the transboundary region, common use of natural resources, and integrated water resources management in compliance with the new European Water Framework Directive.

This second part of the paper presents a short analysis of water resources in the Bulgarian territory. The main problems of the Mesta water use and protection and Bulgarian measures to improve water quality are shortly discussed. The annual discharge of fresh water to Greek territory is estimated. To be able to avoid potential conflicts and issues and to ensure the success of sustainable regional development the paper recommends an approach of share Bulgarian-Greek use of the Mesta water in the framework of EU and forthcoming integrated river basin management.


In Bulgarian territory the Mesta River length is 129.5 km or about 50 % of the total length. There are 24 tributaries without the Dospatska river. Its tributaries rise from the highest Bulgarian mountains Rila, Pirin and West Rodhopi and they have high slope. The Dospatska/Despatis river is the biggest left-bank tributary in Greek territory, however almost all catchment area is in Bulgaria. The Mesta catchment is rich of water resources. At the territory is formed about 6.5 % of the Bulgarian fresh water discharge. The Mesta River and its wetlands is more natural and in a better state than many found in Europe, and may have less difficulty than expected in complying with the EU requirements, (WWF, 2000). It offers a great natural wealth and is among the pearls of Europe.

There are 22 hydrometric gauging stations installed in the basin, from which 5 on main steam and rest on the tributaries. They all belong to the National river-monitoring network of Ministry of Environment and Water (MOEW). The distribution and density of the gauging stations is adequate for water-resource assessment of the territory.

The Mesta River flow is estimated at the Bulgarian-Greek border, aiming to assess the average annual volume discharging into Greece. The assessment is based on 29 year series (1955 – 1983 inclusive) of measurement data from the Hadjidimovo gauging station closest to the Geek border (23 km), independent of water consumption in the basin and the volume of diverted water to other river basins. We consider such an approach as more objective because is difficult to evaluate the real water consumption and it may arise some pessimism of the border water balance on the basis of the so called natural discharge. The flow at the border is calculated according to (Ivanov et al., 2002):

, m3/s

where Q??.?.??. and Q??.?.? are mean annual discharges at the border and the Hadjidimovo station respectively; Q??.??.?.? = 30.695 m3/s for that period with variation coefficient ?v = 0.2569 and mean probability error ?0 = 4.77 %; F?? = 2768 km2 – catchment area up to the border with average level of 1318 m a.s.l.; Fx = 2260 km2 – catchment area with average level of 1310 m a.s.l; ??? = 12,709 l/s/km2 – basin discharge module at the border river section; ?? = 13,582 l/s/km2 – basin discharge module at the Hadjidimovo station. Then the average fresh water discharge to Greek territory is Q??.?.?? = 35.178 m3/s and annual water volume is 1109.37 mln m3. With the same approach Q??.?.?? = 41.533 m3/s according to the 1945/46 – 1974/75 data of hydro-metric register.


The Mesta River is used for: irrigation, domestic use, energy production, fishery, tourism, and waste disposal.

2.1 Industry and domestic needs
An idea of potable and industrial water use in the basin can be obtained from the National Statistic Institute data (Ivanov et al., 2002), Figure 1. Here the drinking water consumption includes also its use for industrial consumption. Both surface- and ground-waters are used, and ground-waters account for significant percent. Almost all water is redirected back to the stream after its use, and this fact is essential when we tackle with water use and water balance.
Figure 1. The Mesta basin water consumption for 1989 (mln cubic m).

2.2 For irrigation
The amount of water used for irrigation has sharply declined in Bulgaria during transition. The problem is important for the future development of agriculture and allocation of the country’s water resource. A further study should concentrate on how institutional factors, in particular legal and de facto property rights on irrigation systems and irrigation governance, are affecting water usage. At the moment one can conclude that land fragmentation in the region in the wake of decollectivization and restitution has contributed to irrigation decline. However a study before 1989 shows that the total agricultural Mesta-valley land which might be irrigated accounts 18292 ha (Ivanov et al., 2002). The gross water volume for irrigation of those lands, if we accept 2000 m3/ha mean watering norm of all crops and a system efficiency 0.65, will be about 50 mln m3 annually.

2.3 For electric power production
Small water-power stations have been constructed – Toplika, Yakoruda, Razlog and Bansko with total power of 1.542 MW. In Dospat catchment area there are two dams – Dospat dam and Shiroka poliana dam, which are utilizing for electro-production and for transferring of water to other river valley. The Mesta River has the highest water-power potential in comparison with the other river in the country (Figure 2), and very high specific water-power potential (Figure 3), which is utilized in Greek territory.

Figure 2. The Mesta River power potential in comparison with other Bulgarian rivers.

Figure 3. Specific water power potential of the main Bulgarian rivers at the state border.

2.4 Diverting to other river basins
In spite of availability of many ideas and designs of total assimilation and use of the Mesta water, at the moment only few water transfers to internal territories are implemented. They are summarised as follows (Table 1, according to published design data):

Table 1. Annual water volumes by project data diverted to other territories during winter and spring period.

from To Project water volumes,
mln m3
Granchar and Djefaritsa canals Belmeken dam 77.6
Veshteritsa and Kanina canals Dospat dam 68.7
Bistritza canal Dospat dam 18.0
Total 164.3

From the analysis of the Mesta-basin water consumption is evident that it is basically by domestic consumption, industrial consumption, and by irrigation, Figure 4.

Figure 4. The Mesta basin total annual water consumption in mln m3.

The total annual water need of the population in the basin is 84.822 mln m3, from which at the moment is consumed 17.22 mln m3 annually.


Bulgaria has always given attention to the protection of environment and water.

3.1 Programmes and Strategies Being Implemented (OECD, 2001):
National Waste Management Programme (1999)
National Programme for Priority Construction of Waste Water Treatment Plants (WWTPs) (1999)
National Biodiversity Conservation Strategy (1999) and Action Plan (2000)
National Programme for Phasing Out Production and Use of Leaded Petrol (1998)
National Action Plan on Climate Change (2000)
National PHARE Instrument for Structural Policies for pre-Accession (ISPA) Strategy – Sector Environment (1999)
Programme for the Transposition and Implementation of EU Environmental Legislation (2000)
Programme for Water Resources Conservation in conditions of Drought (2001)
National Environmental Strategy and Action Plan 2000-2006 (2001)
Being Prepared: River Basin Management Plans

In order to realize sustainable development in the river basin and in accord with the international agreements, Bulgaria takes structural and non-structural measures to manage water resources as follows (MOEW, 2000):

3.2 Non-structural measures:
Protection of important areas for water sources and conservation of forest and vegetation areas including reforestation; Optimization of water usage including improvement of excessive water use and optimization of water balance in the river basins through integrated operation of reservoirs and operation of intakes, irrigation systems, hydropower systems and water supply systems; Optimization of reservoir operation so that to keep sufficient base flow along the rivers for improving water quality and maintaining fauna and flora around the river courses. Provision of green belts along the river for controlling runoff of polluted water and suspended materials from non-point sources and soil erosion areas; Providing forest and vegetation for controlling soil erosion and runoff from contaminated areas of soil; Improve and strengthen monitoring and information systems.

While both nations engage in some monitoring, at the international level there still is no effective monitoring and management of the Mesta River water quality. Since 1992 the Ministry of the Environment and Water (MOEW) has been responsible for monitoring and pollution control for all surface and underground water. Sampling and analyses of the water quality are performed by Regional Inspectorates for Environment and Water (RIEW) of MOEW. The major sources of water pollution in the Mesta region are municipal waste waters and industrial effluent, which are being released with inadequate or no treatment. These sources are generally being identified by the RIEW of MOEW.

3.3 Structural measures include:
Improving water supply systems, irrigation systems, and hydropower facilities; Waste-water treatment plants (WWTPs) for municipal and industrial wastewater; Water recycle systems for the industries.

Projects and constructions of WWTPs are planned to commence for Mesta basin. The National Program for priority construction of urban WWTPs for settlements with over 10000 equivalent inhabitants in Bulgaria includes especially for Mesta basin 2 new WWTPs and 1 for extension, reconstruction and modernization (Dontchev, 2001). Razlog is a small town in the Mesta valley with a population less than 13000, supplied with drinking water from central supply network, and currently about 90% of the population are serviced by the build sewerage. The commenced WWTP with full biological treatment will result in the removal of 85-95% of the incoming pollution load, and will serve more than 15000 inhabitants. The design is for extended aeration process and mechanical sludge treatment.

3.4 Financing and investments
In difficult economic times it is mobilizing different sources of funding. Parts of the projects will be financed separately or jointly by State Budget, National Environment Protection Fund, the PHARE Program or other international sources. Direct budget subsidies for the environment from the state and municipal budgets are directed toward construction of town water purifying stations and depots for household wastes. However the share of these subsidies decreases permanently (from 37% in 1993 to 3% in 1996 of GDP). Figure 5 shows the site of Hadjidimovo monitoring station and the new Solid Waste Depo of town of Gotze Delchev, serving not only the town but also surrounding villages, total population about 23573

Figure 5. View of the Mesta river at the Hadjidimovo monitoring station situated at 23 km from the Greek border (last in Bulgarian territory) (left), and the new Solid Waste Depo of town of Gotze Delchev for population of 23573 (right).

The National Environmental Protection Fund and Municipal Environmental Funds are effective sources of financing. They compensate for the lack of credit capital from trade banks. Using the principles “the polluter pays” and “shared responsibility” the National and Municipal Environmental Funds collect off-budget resources which are used for financing important investment projects. This type of financing is usually grant or credit without or with a low rate of interest for borrowers. The aim is to support environmental investment activities during the period of transition. The European Committee (PHARE and other programs) is funding monitoring stations, WWTPs, scientific studies of transboundary pollution, and the establishment of warning systems for the areas threatened by siltation and flooding. Such a station, as mentioned above, has been constructed recently in the northern section of the Mesta River. The Japan International Cooperation Agency (JICA) and the UNDP also have funded projects designed to improve water management in Bulgaria.

The WWTP for the town of Razlog has applied for financing by ISPA (Instrument for structural policies for preaccession). This investment is justified by the anticipated benefits to the natural resources development in the Mesta River as a transboundary water course and to the health of the community, as well as to the improvement of agriculture, fishing and property values (Dontchev, 2001). Thus the project is fully financed through grants, i.e.: PHARE CBC financial instrument 75%, and Bulgarian government grants 25%.


The main problems of the Bulgarian territory concerning the Iron Curtain project, identified during our field trips and Bulgarian-Greek common visits to the region in 2002, are :
water resources of the region
water quality
the Network of river hydrometric stations
solid waste and industrial waste treatment
forest and its importance

Having in mind the water-resource study in the region and the lack of an effective monitoring at international level, and to avoid possible issues between the two countries, a new water quality monitoring station closed to the Bulgarian-Greek border should be built. It will serve the two countries and will be a supporting point in the forthcoming integrated river basin management of the Mesta water.

As the priority of the IC project is the social and economic development of the transboundary region and share use of natural resources, the integrated water resources management of the Mesta/Nestos River basin is a key topic. Environmental, economic, and social benefits that are likely to arise from the implementation of such a share use of water resources could be significant.

Until 1989 almost all preliminary concepts of the experts and the numerous decisions concerning the use of the Mesta River waters in Bulgaria are based on the fundamental logic: after the complete satisfying of the necessities of the population in the catchment area in perspective, the residual water resource will be used through its transfer to other river valleys. (However there are realized projects for an insignificant part of the residual water resource.) This logic is preserved in the developed and developing project decisions after 1989, as the quantity of the residual flow is conformed with the requirements of the agreements between Bulgaria and Greece from the end of 1995 (State Gazette, 1996) concerning the Mesta River flow. ?his approach is logic and juristically well-grounded, but when the flow of a transboundary river between two neighbour (and beside that friendly) countries, with relatively close objectives within the framework of the European Community, comes into question, the problem ?f using the Mesta River flow, in our opinion, must be solved by ?stimating the benefits and damages for the both sides from the ?ventual transfer of about 450 – 500 mln m3 for an average year in other river valleys in Bulgaria. ?his undoubtedly depends on the good will of the both countries to search and find a decision, based on the economic balance, the mutual benefit and usefulness. Several large-scale reservoirs and water power stations are built in Greece, an acute shortage of irrigation water is felt ?nnually, complex ecological problems in the Mesta River delta are apparent even now, and if some 50% of the river flow, formed in the catchment area in Bulgaria along the Mesta River, are diverted, these problems will intensify and may take even a catastrophic turn. Obviously the river basin management and water use in the framework of the concepts and decisions of the EU are more than necessary in a situation like this, but not without the mutual benefit of the both sides and the good will of the both countries. This will is apparent from the Bulgarian side, not because we are candidate member of the EU, but because this is maybe the best that can be done for development of the region as a whole. It would be improvident to wait and to think that the question of the Mesta River flow can keep in future this present state, which is unfortunately favourable only for one of the sides. We hope that all these is understood not only by the experts and scientists, but also by the politicians of the both countries. We need to unite the scientific and political thought with the economic practice.

The challenge lies in raising the political will to implement water-related commitments. Water professional need a better understanding of the broader social, economic, and political context, while politicians need to be better informed about water-resources issues.

The authors gratefully acknowledge the support of the research by the European Commission’s Fifth Framework Programme, part “Quality of life and management of living resources”, contract reference: QLRT-CT-2001-01401. The authors are solely responsible for the content and it does not represent the opinion of the Community, the Community or Bulgarian Academy of Sciences is not responsible for any use that might be made of data therein.


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Ivanov, I., E. Bournaski, L. Apostolova (2002) Water problems of the Mesta/Nestos transboundary river in the Bulgarian territory, (submited for publication).
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