This article discusses the changing role of municipalities in the control of new environmental problems. The definition of environmental problems changes over time. It could be said that the change mirrors a learning pro¬cess, whereby the most prominent problems are solved first. Single source emissions have been dealt with and now diffuse emissions are increasingly becoming the environmental challenge.

The results of an empirical study of four environmental projects concerning the control of diffuse emission are presented with regard to the new role of municipalities. This study shows how municipalities are moving from their traditional control and supervisory role to a cooperative and "joint-vision" role.

The concept of joint vision involves a competence development of interest groups that are not fully informed and that partially have competitive roles. Joint vision demands a leadership that encourages open undertakings and personal responsibility not supervision and control by others.