The UNECE (United Nations Economic Commission for Europe) recently published their Second Assessment of transboundary waters for the European and Asian parts of the UNECE region.
The Second Assessment provides a comprehensive overview of the status of transboundary waters, covering more than 140 transboundary rivers, 25 transboundary lakes, about 200 transboundary groundwaters and 25 Ramsar Sites or other wetlands of transboundary importance.
It has been carried out under the auspices of the Meeting of the Parties to the Convention onf the Protection and Use of Transboundary Watercourses and International Lakes (Water Convention), in close cooperation with water and/or environment administrations of some 50 countries and with involvement of more than 250 experts.
IGRAC previously contributed to the 1st Asessment in 2007 and now provided all transboundary aquifer mapping for the recent 2nd Assessment (published Autumn 2011), such as the maps seen below. More information as well as a copy of the report is available here.