We present the concept and first experiences for a web-based ecological knowledge management system ILMAX. It manages experience knowledge resulting from an ecological long-term investigation of the regeneration process of the stream Ilm (Thuringia, Germany). The tools used are iZone, a web-based content management system with an emphasis on information retrieval and feedback, and D3, a tool kit for building knowledge-based systems and for managing case bases. The difficult initializing phase of knowledge management systems was done by a “knowledge champion” gathering and structuring various kinds of text documents, data sheets and unpublished knowledge of domain experts.