The most common questions asked after, or even during, a flood event is “why wasn’t I warned?” or “why wasn’t I told my house/business/vehicle was at risk of being flooded?”
The response typically revolves around how an event was “unprecedented” and didn’t unfold as was forecast.
The reasons why we believe we were not adequately warned don’t always stem from an absence of warning (actual or perceived), but also because of the complexities of understanding the variations in emergency management framework, agency responsibilities or flood watch and warning messages. It’s also beneficial to have a basic understanding of how flooding occurs in a particular area.
As we head into another Australian wet season, it is beneficial to be aware of the basic emergency management framework, the flood risk, how and why warnings are issued and know when to act.
Who does what
The emergency management framework is slightly different in all states and territories across Australia.
At a high level, the emergency management framework is an escalation-based system where increases in impact and intensity results in an escalation through levels of government. The key is that each level of government has responsibilities which are matched to its capacity, capability and applicable legislative requirements.
Credit: AIDR Handbook Collection – Australian Emergency Management Arrangement
In Queensland, for example, support and assistance can be escalated through the four tiers, starting with local government and moving its way up to the federal government. Each tier has a Disaster Management Group (DMG) and Coordination Centre (CC). The DMG is responsible for planning, organising, coordination and implementation while the CC supports the DMG in coordinating information, resources and services required.
Credit: Queensland Prevention, Preparedness, Response and Recovery Disaster Management Guideline
This approach allows for those who are closest to the event, with the highest level of situational awareness, to have ownership of the response and the ability to escalate should the size, intensity or impact of the event exceed their capacity and capability.
In addition to DMG and CC there are also functional lead agencies such as the Bureau of Meteorology, who have a legislated role in collecting data and providing flood warnings.
How does the Bureau of Meterology fit in?
Under the Meteorology Act 1955, the Bureau is responsible for meteorologic forecasts and issuing of flood watches and flood warnings. The practical delivery of flood forecasting and warnings are delivered under a standard level of service (SLS) document in place for each State and Territory.
The Bureau provides forecasts for catchments with a response time of six hours or greater. For flash flood catchments (flood response time less than six hours), flood forecasting responsibility is devolved to local governments.
What does this mean?
Flood warnings may come from a variety of sources. Local governments, or in some cases the SES, may issue flood warnings for smaller creeks and tributaries where rain to flood times are less than six hours, or they may also take predicted flood levels from the Bureau for larger river systems and provide inundation extent maps.
The Bureau will issue flood watches and flood warnings as outlined in our previous post. These warnings typically relate to agreed gauge locations within the catchment and provide a qualitative or quantitative flood level forecast.
Therefore, it is important to understand the flooding mechanisms which affect your area of interest and seek information from the relevant agency regarding the potential flood risk.