The need for public participation is gaining increasing attention in environmental management in general, and specifically in the rehabilitation of degraded river corridors. Web-based Public Participation GIS (PPGIS) methods are one way of addressing this demand and complementing traditional participation formats, since they are more flexible in time and space and offer the advantage of anonymity for the ‘silent majority’. However, the use of digital technologies creates new challenges for planners and citizens. Hence, it is very relevant to investigate the usability and applicability of real life PPGIS tools during participation processes. The aim of this study is to evaluate the usability and applicability of a web-based PPGIS tool. A mix of quantitative (survey) and qualitative (focus group) methods was employed. The results of the survey show a medium-high usability of the tool, but reveal a digital divide based on age, gender and education level, potentially excluding citizens based on socio-demographic characteristics. Simultaneously, the tool provided an opportunity to participate for citizens who had little prior experience in this respect. In the focus group, participants generally embraced the tool's qualities, such as its multi-scale spatial approach and the opportunities it affords citizens with regard to education and empowerment. In addition, participants identified points for improvement, such as simplifying way-finding, integrating two-way communication functions and using smartphone technology.