Rapid, hyperlocal flood impact predictions help authorities and communities prepare.
During a flood event in March 2021 in the Logan Albert Catchment (Queensland), FloodMapp worked with the State Disaster Coordination Centre (SDCC) through Queensland Fire and Emergency Services (QFES) to rapidly implement FloodMapp ForeCast for emergency use.
With high intensity rainfall (up to 509 mm) recorded upstream in the catchment, a major flood was forecast for the Logan River. The Bureau of Meteorology (BoM) issued a major flood warning for the Logan Albert River Basin. At the time the warning was issued, 08:08 on Tuesday the 23rd of March, the Logan River at the town of Beaudesert was at 7.32 meters and rising. The official warning advised - the flood was expected to exceed ‘major flood level’ of 8.3m that day, but not expected to exceed the 2017 flood peak of 14.76m (the variation in impact between these two peaks is demonstrated below).
FloodMapp were asked whether they could provide a more detailed forecast intelligence to enable emergency managers to more accurately assess the potential flood impact. To take timely and appropriate action to protect people and property, and plan an evacuation, emergency responders needed to translate the peak river height forecast provided, into a forecast flood inundation map. The range of the expected peak (8.3m to 14.76m) meant that impact areas, community warnings, and evacuation planning were uncertain and being delayed. More information was needed so that QFES and Queensland Police could take action.
FloodMapp assisted by providing a peak inundation forecast map.
Using FloodMapp ForeCast, powered by DASH, the FloodMapp team not only predicted that the river-peak at an upper limit of 12.5m, but could also produce an inundation map. The forecast model was developed and delivered to QFES emergency operations planners within 75 minutes of the request. Planners were then able to model evacuation needs for 11.5m, 12m and 12.5m scenarios.
FloodMapp ForeCast was rapidly ingested into QFES ArcGIS online portal as a digital map. The data interoperability meant that the SDCC was able to overlay the FloodMapp ForeCast maps with their internal population and asset datasets to provide situational awareness of the potential flood impact to people, property and critical infrastructure. It also facilitated a shared common operating picture with other agencies in the Queensland Disaster Management Arrangements (QDMA). With this speed and level of accuracy, deployed as a common operating picture, QFES and Queensland Police Service (QPS) was able to rapidly pinpoint impacted properties and plan highly targeted, safe, and timely evacuations and community messaging.
This enabled Queensland Police to print a list of properties and begin evacuations, to keep the community safe. Beaudesert State High School students were sent home before they may have been trapped by flood waters.
The Logan River at Beaudesert peaked at 12.3m on Wednesday the 24th of March.
“What FloodMapp produced was really valuable and when matched with QFES mapping technology meant that disaster management agencies could immediately identify at risk properties. It also allowed us to print a list of properties and begin doorknocking in plenty of time to allow residents to prepare for the possible flood,”
- Senior Sergeant Mike House.
In the critical phase of planning and transitioning to damage assessment and recovery the Queensland Reconstruction Authority was also able to access the Common Operating Picture data through the same portal. With this data, QRA was able to undertake rapid spatial analytics of exposure to people, property and infrastructure to answer strategic level questions from the Queensland Premier’s office. This data enabled all staff at the strategic, operational and tactical levels to maintain real-time situational awareness before, during and after the flood.