Separation of overland flowpaths based on depth and depth velocity product
OVERLAND FLOWPATH SEPARATION
Approach and Outcomes
We developed separation criteria based on depth and depth velocity product to separate flooding arising from overland flow into the two categories. For each township we applied these criteria using ArcGIS. We then manually edited the result of this process to develop polygons suitable for implementation to the Planning Scheme update. We also performed a statistical analysis to inform Council of the magnitude of the areas of potential concern.
In 2014, Toowoomba Regional Council successfully completed 42 flood studies for 35 locations. For ten townships, both riverine and overland flows were modelled and mapped. For each location, the overland flow component had been separated from the riverine component, however substantial variation between the severity of overland flow existed. The purpose of this project was to separate the overland flow areas into two categories based on severity to assist with decision making and implementation to the Planning Scheme update.
Toowoomba Regional Council