In 2002 and 2008 two hydroelectric power plants (HPP) were built in Sevnica. Such big spatial planning projects usually have a considerable impact on nature and imply a deterioration of living conditions for all species living in the affected area. Presently, a regulation of the area of influence of the Blanca HPP is planned in Sevnica, which is partly aimed at restoring its biotopic function. By applying human dimension research methods the research tried to determine, if the relevant stakeholders are acquainted with the various natural elements of the Sava river ecosystem and if they would supporta fully sustainable regulation. It also tried to find out whether they were prepared to actively participate in the sustainable regulation project and, finally, if their reactions conformed to the stances expressed in their written answers. Based on a study of the relevant literature the theoretical framework for the research was defined, while in the following stage 17 stakeholders of the area were identified by using a combination of methods. Then a semi-structured interview was conducted with 10 stakeholders who consented to participating in the survey. The research has shown that stakeholders are only partly familiar with the natural elements of the river Sava ecosystem (on the scale ranging from 'familiar', over 'partly' to 'not familiar'), but that they strongly support a sustainable regulation (on a scale ranging from 'strongly', over 'partly' to 'not supporting'). Moreover, they resulted to be very prepared to participate in the project (on a scale ranging from 'very', over 'partly' to 'not prepared'). However, the overall reactions of the stakeholders were not always compatible with their written answers. In conclusion, the research has indicated that the use of educational methods enabling a holistic approach to ecology involving eco ethics would improve the stakeholdersʼ knowledge and thus enhance more responsible decision-making.