Having joined the NEI in 1970, Teun Botterweg (1943) has over 35 years of professional experience, both within and outside ECORYS-Nederland BV, in which NEI now is integrated. At present he works mainly in Technical Assistance and Training In the field of (the economics of) Water Management (WM). This includes national and transboundary institutional aspects of  WM, as well as Public Participation and Communication. The region of expertise of Teun Botterweg is mainly Central and Eastern Europe (practically all countries including Turkey). However, he has also worked in Asia, Africa and Latin America in various countries.
Between 1990 and 1994 he was attached to the Hungarian Ministry of Environment and Regional Planning as management advisor (EU Phare - programme cycle management for environment, water and nature, and TA to the Central Environmental Protection Fund). Then he spent a further five years (1996-2000) as team leader of the Co-ordination Unit of the Environmental Programme for the Danube River Basin (EPDRB). This related to the development of the International Commission for the Protection of the Danube River (ICPDR). As such, he was responsible for co-ordination of EU support to the EPDRB and for management and supervision of a large volume of specialist technical inputs in the fields of environmental planning, River Basin Management Planning and wetland management.
After the year 2000 he was mainly involved in introduction and development of the application of the EU Water Framework Directive in various CEE countries like the Baltic states, Bulgaria, Romania and Turkey. All this included many training events, in which Teun Botterweg played a key role in organisation, training programme development and implementation (in the widest sense).