IYU Carpark Experiment, Pakenham

Study site at the IYU Carpark

This design aims to retain large volumes of stormwater in the landscape to support street trees. Although we are testing this design in a carpark, we have manipulated the system/catchment area ratio (10%) to mimic the intended application: a typical street in a new residential development.

Key design elements:

  • a grated inlet pit with a sump to intercept sediment takes flows from the impervious catchment
  • flows are conveyed by 225 mm solid pipe to a structural soil trench
  • 225 mm slotted pipe in the trench promotes exfiltration
  • a 300 mm deep reservoir in the structural soil trench is created by a riser in the downstream pit

Layout of experiment

Experimental design

The experiment has three treatments:

  • Tree planted as per standard (control treatment)
  • Trees planted next to a structural soil trench not receiving runoff
  • Trees planted next to a structural soil trench receiving runoff from the carpark

We’ll be monitoring tree growth, stormwater volume capture and flow rates in the experiment for approximately 18 months years (July 2021 - February 2023).

Project status

Construction was completed by Kent Environmental & Vegetation Management in June 2021. Trees were planted in July and monitoring will begin soon.

Project team

The experiment at the IYU Carpark represents a collaboration between Cardinia Shire Council, Melbourne Water, Afflux Consulting and researchers from The University of Melbourne. This work is supported by the Livable Communities, Livable Waters Program.