An apparatus which includes a mounting, a plurality of detectors provided to detect a condition of at least on parameter indicative of presence of one or more materials in a gutter channel and data processing capabilities. A sequence of signals are transmitted and received when the apparatus is in a detection mode, and the data processing analyses the received signals to provide an indication if a material is detected as being present in the channel and, if detected, a type of the material. On the basis of this analysis and identification of material, decision can be made as to whether any remedial action is required to clear the material and/or decide upon an ongoing monitoring and maintenance.