LISMORE FLOODS. Lismore flood clean up. The town of Lismore starts the mammoth clean up after flood waters engulfed the town. Pic Nathan Edwards
LISMORE FLOODS. Lismore flood clean up. The town of Lismore starts the mammoth clean up after flood waters engulfed the town. Pic Nathan Edwards

EXPLAINED: What Northern Rivers flood warnings mean

NO-ONE in Lismore wants to relive the floods of 2017, where many were caught unawares of the natural disaster when it struck.

This explainer should help you over the next few days, should the heavy rainfall forecast result in localised flooding.

There are different levels of warnings issued by the Bureau of Meteorology.

Before a potential flood, the BOM will issue a thunderstorm warning, weather warning or flood watch alert.

This flood watch alert has been issued.

Residents are advised to listen to their local radio station for information updates and advice, find and check emergency kits, check on neighbours to ensure they are aware of the flood watch and locate and prepare to activate their home or business flood safety plan.

The next stage of warnings is the flood warning and the flood bulletin.

A flood warning is issued when the Bureau of Meteorology is more certain that flooding is expected, often when rain has started to fall.

Under this warning, residents are advised to never drive, ride or walk through floodwater, fill their petrol tank with fuel and car with emergency supplies, listen to the local radio station and activate their home or business safety plan.

Stage three involves an evacuation warning.

In this situation, residents are advised to locate important documents, valuables and mementos, put them in their emergency kit, follow emergency services instructions, act early as roads may close or become congested, and stack items on benches or tables, placing electrical items on top and securing objects that may float.

By stage four, the SES will issue an evacuation order.

In this event, residents must turn off the electricity and gas at the mains and secure any gas bottles, take pets with them, never enter floodwater, and follow the instructions of emergency services.

Residents are advised only to return to flood-affected areas once it is declared safe to do so.

Keep in mind that the classification of a flood is subject to change. For instance, a minor flooding warning may be issued, but it may be upgraded to moderate and then major, as rainfall continues and river levels continue to rise.

Minor flooding

Causes inconvenience. Low-lying areas next to water courses are inundated. Minor roads may be closed and low-level bridges submerged. In urban areas inundation may affect some backyards and buildings below the floor level as well as bicycle and pedestrian paths. In rural areas removal of stock and equipment may be required.

Moderate flooding

In addition to the above, the area of inundation is more substantial. Main traffic routes may be affected. Some buildings may be affected above the floor level. Evacuation of flood affected areas may be required. In rural areas removal of stock is required.

Major flooding

In addition to the above, extensive rural areas and/or urban areas are inundated. Many buildings may be affected above the floor level. Properties and towns are likely to be isolated and major rail and traffic routes closed. Evacuation of flood affected areas may be required. Utility services may be impacted.