Description Location: The catchment of the Nestos river is sited at the southwestern corner of Bulgaria and at the area of eastern Macedonia and western Thrace in Greece. The river flows from the mountain Rila (2716m) in southern Bulgaria and after a distance of approximately 230Km in both Bulgarian and Greek territories, it discharges into the Thracian Sea eastern of the city of Kavala. (Greek boundaries 420 00' N-400 51' S, 250 00' E, 230 30' W) General description: Nestos is a transboundary river, with the 60% of the catchment area belonging to Bulgaria and the rest to Greece. A treaty was signed by the two countries in 1995, specifing that 29% of the river's discharge coming from the Bulgarian territory should end up in the Greece. Nestos river was chosen as a reference area, as an example of the promotion of the collaboration of countries for integrated transboundary water resources management, having the special characteristic of Greece being already a European Union member while Bulgaria is being a candidate member and a former Eastern Europe country. The basin is rather deep with an axis of ENE - WSW direction. The basin is seperated in the east by the Abdira - Fanari Ridge, which is mainly composed of metamorphosed rocks. Towards the north, south and west the basin boundaries are granites and metamorphosed rocks sequences of the Serbomacedonian massif. In the basin of Nestos several geothermal manifestastions and geothermal fields exist (for example, the geothermal fields of Eratino - Chrysoupolis and Neo Erasmio - Magana).The mean monthly flow of the river at the bulgarian catchment is about 0.12-1.80 m3/s while at the greek 10-150 m3/s. The climatic condition, land morphology and the presence of water have made it possible for various habitat types to be developed, accommodating over 150 animal and various flora and fauna species. The delta of Nestos river is protected by the Ramsar Treaty. The main economic activities in the catchment are: agriculture, forestry, power industry, cattle breeding and recreation.