Cleaning and Maintenance information Help us protect Tasmanian waterways and parklands - Keep stormwater out of the sewer Sewer flushing information - Sewer flushing occurs so we can ensure your sewage pipes are clear of blockages and working as efficiently as possible. Water flushing information - Flushing is when water is released from a fire hydrant or access point at a high flow rate and is used to clean our water mains.