Flooded Clarence Way near Bonalbo – New South Wales. Image is courtesy of the Australian Broadcasting Corporation.

Kyogle Council

www.bgeeng.com/special-projects/bonalbo-flood-study/
Bonalbo Flood Study

About The Project

Kyogle Council engaged engineering consultant, BG&E, to develop a Flood Study for Bonalbo. The study was undertaken with financial and technical assistance from Council and Department of Planning, Industry and Environment (DPIE) through the New South Wales (NSW) Government’s Floodplain Management Program. The Flood Study helps us to understand the likely flooding scenarios for the town of Bonalbo including flooding from Peacock Creek and runoff from local catchments.

Kyogle Council adopted the Flood Study on the 25 October 2021.

The Bonalbo Flood Study has:

  • developed flood models based on historic data and statistical analysis;
  • identified the areas of flood prone land to assist with flood planning and risk management;
  • considered the effect of the Bonalbo Dam on flood risk;
  • established the likely flood risk and flood hazard for properties in the study area;
  • developed flood mapping to assist in future planning and development; and
  • provided flood intelligence to the NSW SES to assist in flood emergency response.

Study Area

Floodplain Risk Management Process

The study was prepared in line with NSW Government Policy and the Floodplain Risk Management Process. The process consisted of five key stages. The Bonalbo Flood Study will complete Stage 1 and 2 (Data Collection and Flood Study). Now complete, the findings of the Flood Study will enable Council to start to the next step in the Floodplain Risk Management process, that is consider measures to reduce impacts of flooding.

Community Consultation

Community consultation was undertaken at the beginning of this project and received a great response with many photos provided which were helpful in the validation of the flood model results.

Final Report

Detailed hydrologic analysis and hydraulic modelling has been undertaken to map the predicted flood extents, levels, depths, velocities and hazards associated with a range of possible flood types from a one-in-five year flood, up to a one-in-500 year event and the PMF (Probable Maximum Flood) event. The study also considers the predicted effects of climate change on flood behaviour. The information collected from the community about their community’s experiences of flooding has been used to validate the flood model against actual observed flood events.


Downloads and Links


Presentation on the Bonalbo Flood Study

This presentation gives an overview of the study that has taken place at Bonalbo.