A New Solution for real-time flood intelligence in NSW Integrating Coastal Flooding Information

Bronson McPherson and Galen Lewis - Manly Hydraulics Laboratory , 21 December, 2018

MHLFIT is a tool designed to help flood managers and emergency responders make decisions about flood events as they develop. It incorporates real-time and predicted data from a range of sources and provides interactive inundation and timing data in a web-based format in near real-time. Users are able to account for uncertainty by using built in what-if scenario tools and see results immediately. The tool is developed in conjunction with councils and the State Emergency Services (SES) to provide the most important and useful information required for decision making.

Flood prediction in Intermittently Closed and Open Lakes and Lagoons (ICOLLs) is complicated by the highly variable downstream conditions which are constituted by tidal behaviour, berm height, entrance dynamics and morphology, ocean waves, and differing management policies for lagoon entrances. The timing of opening entrances can also have a significant impact on the peak flood level and must take into consideration not only tidal cycle but also the degree of scour an entrance may be subject to. These factors all impact on the actual peak height during a flood event.

A case study will be presented of the Manly and Narrabeen Flood Intelligence Tool which integrates these considerations and provide a means to perform on-the-fly sensitivity and scenario testing to ensure informed decisions are made in an emergency. Additionally, it also incorporates forecast tidal and Bureau of Meteorology (BoM) rainfall predictions into its automated predictions.