The system for scheduling and cleaning canal systems (SCCS) described in this paper serves for a proxi-optimal scheduling of cleaning operations for municipal canal systems. The ranking of the canal sections to be cleaned is provided in two independent ways and the plan is then established by an opportunistic compromise. The main characteristics of the expert system are its adaptability and capability for replacing lacking data in the data-base by default values. The paper reports on practical experience obtained with the SCCS system for a canal network of about 2000 sections.