Event flood modelling of the largest rainfall in the last 21 years

Gunnedah Recorded Rainfall Data Analysis

The town of Gunnedah experienced significant rainfall between the 7^th and 8^th of November 2021, and the runoff generated from the weather overwhelmed the Gunnedah Solar Farm as well as several other sites in the vicinity. Hundreds of homes were damaged, and many residents were ordered to evacuate. Our job? Due diligence to make sure the solar farm project didn’t affect the community.

PCL brought in our Water team to analyze the rainfall data collected from this storm event at the Gunnedah Airport Bureau of Meteorology Station. We provided hydraulic modelling to understand the flooding duration and the generated flood levels at the solar farm project site, as well as on properties adjacent the site.

This storm was the largest recorded at the Airport Station in the last 21 years. Our conclusions? The hydraulic modelling indicated that the proposed works did not adversely impact the duration of inundation at neighbouring holdings.