The GCRC are working collaboratively to undertake a catchment-scale litter assessment. The project is being undertaken in two phases with an initial assessment on litter source generation completed in January.
The initial phase of the Gardiners Creek (KooyongKoot) Litter Assessment was undertaken by Alluvium in January 2024. This Rapid Assessment was undertaken with the objective of understanding where the major sources of litter generation were located within the catchment, how water flowed from these areas to waterways, and what infrastructure was located on these pathways of flow, to understand whether current infrastructure was adequate or whether new investment was likely to be needed. Finally, the assessment focussed on possible new locations for Gross Pollutant Traps (GPTs).
The method used for the assessment was subset of the Litter Assessment framework developed and applied previously at the Moonee Ponds Creek and Lower Dandenong Creek catchments. This method focusses on using land-use, litter collection and drainage data to establish high risk areas for litter, pathways of flow from these locations, accumulation areas along the creek and current – and possible new – locations of/for infrastructure.
The output of this initial assessment phase came in the form of a report including detailed maps, images and in GIS layers. This report identified the following:
- Regional litter hotspots
- Local litter hotspots
- Pathways of flow
- Locations of infrastructure along pathways (I.e. GPTs and litter traps)
- Possible new locations of GPTs, ranked in order or priority to treat each Litter generation hotspot
The collaboration used this initial report to guide a grant submission to invest $2,000,000 in upgrades to existing and installation of new GPTs.
The next phase of the assessment will focus on the following:
- Detailed assessment of all current stormwater infrastructure along key pathways of flow from identified litter generation hotspots.
- Proposed investment into infrastructure and upgrades to existing. Ranked by priority.
- (i) Ground-truthing of proposed recommendations to infrastructure investment, and (ii) high-level of design of final recommended infrastructure improvements
The Collaboration plans to the outcome of this full assessment on litter generation hotspots and associated infrastructure to guide investment into stormwater infrastructure in the catchment within the next few years. And, to guide litter management, clean-up and education strategies across the catchment.