Client: Fresh Zest

Project Summary:

Afflux Consulting was approached by Fresh Zest to conduct a flood study of a proposed glasshouse development in Leongatha North. Of particular concern to this investigation is the impact of the proposed development on Ruby Creek which runs through part of the subject site. Given that Ruby Creek is an ungauged and unmapped system with a large upstream catchment, a to understand the flood flow expected at the development site in a 1 in 100 year ARI (or 1% AEP) flood event. Existing and developed flood cases were modelled to examine the impact of the development on Ruby Creek flow path and recommendations have been formed based on this analysis.

Project Outcome:

The investigation defined flows for the Ruby Creek Floodplain upstream of the Strzelecki Highway. The flood extent of these flows across the floodplain has been modelled and the impact of the development investigated. The outcome found that even with a conservative flow rate of 57m³/s assumed for the 1 in 100 year ARI peak flow, there is no significant impact on Ruby Creek as a result of this development. For the development to proceed the following conditions were set:

• A floor level of 52.6 grading to 52.1 at the southern end should be set to ensure no flooding of the site will occur during a 1% event.
• The Glasshouses should be placed on the site as proposed in this report and the associated design drawings. Any relocation, in particular in a westward direction will place further impacts on the floodplain. The orientation should also be maintained.

Key Features and Innovations:

• Hydrological methods used to model Ruby Creek and its floodplain.