Lake Peipsi/Chudskoe Lake Peipsi/Chudskoe Basin – Lessons Learned Gulnara Roll, Aija Kosk, Estonian Agricultural University Peeter Unt, Natalia Alexeeva, Peipsi Center for Transboundary Cooperation Introduction Lake Peipsi/Chudsko-Pskovskoe, sometimes called Peipus (further Peipsi), is the fourth largest and the biggest transboundary lake in Europe. Its three names originated from three languages historically used in the region – Peipsi came from Estonian, Chudsko-Pskovskoe from Russian and Peipus has German roots. Lake Peipsi belongs to the water basin of the Narva River (or Narova), a 77 km long watercourse, which connects Lake Peipsi with the Gulf of Finland of the Baltic Sea. Estonian and Russia share the Lake Peipsi and three countries, including Estonia, Russia and Latvia, share Narva River basin. Latvia has only 5% of the water basin and pollution from its territory is very small in the overall pollution load in the basin. What makes the Lake Peipsi specific and different from other great lakes of the world is that it is located on the future European Union border with Russia and is shared by countries in transition. Estonia regained its independence from the Soviet Union in 1991. Before that Lake Peipsi was an internal big lake in the northwest of the Soviet Union where the same legislation, procedures, environmental standards were applied for the whole lake basin and therefore it is a new transboundary lake. With these radical political changes at the beginning of the 1990s, the socio-economic context of water management also changed drastically as existed earlier economic contacts across the lake were disrupted with the establishment of border customs control on the border between Russia and Estonia. In May 2004 Estonia is expected to join the supranational European Union (EU) and Lake Peipsi will become a transboundary lake shared by Russia and the European Union. Estonian legislation and environmental management system have been adjusted to incorporate requirements of the EU legislative and institutional framework. In the field of water management, requirements of the EU Water Framework Directive as well as of other relevant EU directives are being incorporated into the Estonian framework for water management. The EU legislation, norms and standards are different than the ones of Russia. The main challenge for the future development in the Lake Peipsi Basin is a growing gap in socio – economic development as well as in formal frameworks, including norms and standards; as well as practices, and information between different sides of the border. In this new institutional context of a lake management by one future EU member state and one non-EU member state, there is a need to rethink the coordination mechanism of implementation of pollution abatement strategies in this transboundary lake basin. Background Lake Peipsi is a part of the Narva River water basin whereas water basin area of Narva River itself is 877 km2 or only 15% of the total area. The mean annual water discharge via the Narva River into the Gulf of Finland of Baltic Sea is 12.6 km3 (approximately 50 % of the average volume of Lake Peipsi). The Narva River basin is located in the central part of southeast coast of the Baltic Sea and has an area around 56,200 km2, which is 3.6 % of the total area of the Baltic Sea Basin. Three countries share the Narva River/Lake Peipsi Basin: Russia (36,100 km2 or 64.3 %), Estonia (17,000 km2or 30 %) and Latvia (3,100 km2 or 5.5 %). The main part of the Lake 1 Lake Peipsi/Chudskoe Peipsi water basin is situated on the border of the Republic of Estonia and the Russian Federation between Lake Peipsi Lowland (eastern border of Estonia) and East-European Plain (Russia). Coordinates: latitude 57o 51’ – 59o 01’ (N), longitude: 27o 30’ – 27o 56’ (E). The lake consists of three unequal parts: the biggest northern Lake Peipsi sensu stricto (s.s.) /Chudskoe, the southern Lake Pihkva/Pskovskoe and the narrow strait-like Lake Lämmijärv/Teploe connecting Lake Peipsi s.s. and Lake Pihkva. Morphometric data on Lake Peipsi at the water level of 30 m above the sea level is described in the table 1. Table 1. Morphometric data on Lake Peipsi at the water level of 30 m above the sea level (Jaani, 2001) INSERT TABLE 1 HERE The submeridionally elongated catchment area of Lake Peipsi ranges approximately 160 km in width and 370 km in length. The catchment area of the lake (including the lake surface) has an area of 47,800 km2, of which 16,323 km2 is in Estonia, 27,917 km2 in Russia, and 3,560 km2 in Latvia. It is part of the basin of the Gulf of Finland and is connected with the latter via the rather short River Narva. The lake basin holds more than 4,500 lakes. The largest of them is Lake Võrtsjärv (270 km2). Without Lake Peipsi all the lakes form about 2% of the basin and Lake Peipsi adds 5%. There are about 240 inlets (including tributaries) into Lake Peipsi. The largest rivers are the Velikaya (catchment area 25,600 km2), the Emajõgi (9,745 km2), the Võhandu (1,423 km2), and the Zhelcha (1,220 km2). They altogether make up about 80 % of the whole catchment area of Lake Peipsi and account for 80 % of the total inflow into the lake. Water budget in the lake in general could be described as follows: Total inflow into the lake: 324 m3/s Total outflow from the lake: 329 m3/s (via the Narva River) Residence time: 2 years Genetically, the lake basin is a landform, scoured mainly by the Pleistocene glaciers. Geologically the basin is formed by sedimentary rocks belonging to Cambrian, Silurian and Devon systems. Close to Narva River, Cambrian sediments create so-called clint along Finnish Gulf. Between this clint and the northern shore of the Lake Peipsi the territory is formed by Silurian sediments represented by limestone, marl and dolomite. Upper layers content oil shale, which is intensively used in the mining industry. Silurian limestone has high hardness and form Narva and other waterfalls. From structural-geological and tectonic perspectives, the lake basin is a part of Russian platform, located in transit zone between Baltic shield and Moscow and Baltic syneclises. The stratification depth of the crystalline foundation in the northern part of the basin does not exceed 150 m, in the central part of the basin - within the limits of 250-350 m and in the southern part is lowered up to 1,600 m from a surface level. Regarding its hydrogeological status, the lake catchment is an eastern flank of Baltic artesian basin. Shores of Lake Peipsi: scarp (cliffed, sandy, morainic, peaty) and flat (till, sandy, peaty, silty). Scarp sandy beach is prevailing in the northern part of the Lake. Flat shores are usually swampy, with reed and bulrush. This kind of shores spread mainly on the western part of the lake. 2 Lake Peipsi/Chudskoe Narva has two waterfalls – Omutinskie and Narva waterfalls having the maximum high around 7 m and width 125 m. Unfortunately at present Narva waterfalls are dry due to the derivational channel of Narva hydropower station. This station caused an appearance of Narva reservoir formed by the dam of power station in 1955. This reservoir nowadays is also used by two thermal power stations (Baltic and Estonian) working on the oil shale. There are 29 islands with total area of 24 km2 or 0.7% of the total lake area. Climate. Lake Peipsi is located in the zone with moderate continental climate, rather wet, softened by a comparative closeness of the Atlantic Ocean. The location on the border of the climate transition zone from marine to continental results in the unstable character of the weather in all seasons. Summer is comparatively warm and wet, and there is a comparatively mild winter. Then more continental character increases to the east, where winter is longer and summer is warmer. In general average temperature has an increasing trend that corresponds to global trends. Freezing season usually comes at the beginning of December and ends in the first decade of March. Usually stable snow cover appears in the beginning of December although in cold years it could be the beginning of November or even October. In warm years snow covers the land in January or in February. Maximum thickness of snow cover for the lake basin is around 45-50 cm.; in some years it is up to 85 cm., although minimum values do not exceed 5 cm. During 1929-1998 at Tiirikoja the rainiest month has been July and the driest month March (Figure 5). The average annual amount of precipitation at Tiirikoja during this period was 575 mm. The most frequent wind directions are west (19%) and southwest (18%). This is related to the features of general atmospheric circulation at this latitude that is characterized by the western airflow. Wind direction has seasonal character. Considerable area of the lake causes local changes in general atmospheric circulation that creates definite local circulation in the form of breezes and local winds created by different water and land surface roughness. The lake basin is located in two native zones – taiga and mixed forests. The sub-zone of southern taiga is located to the north of Pskov latitude and mixed forests are spread to the south. Southern taiga forests are mainly coniferous with oaks, lindens, maples etc. The unique ash forests are located in Slantsy region. Small-leaved trees dominate in sub-taiga forests – birches, aspens, alders etc. Wetlands are covered by the same species. Animals are represented by elks, wild boars, roebucks, lynxes etc.