CompletedWe’ve rectified the outlet structure of Thornhill Park retarding basin and wetland, to naturally balance water levels within the system as designed. Landscaping works began in early 2025, with further soil preparation and planting due for completion by mid-2026.
Why this project is important
The Thornhill Park retarding basin reduces flood risk to surrounding homes.
It is one of 200 basins we manage: reserves of low-lying land designed to collect water during heavy rain. Water is then naturally treated within the wetland system before being slowly released back into the environment, following the natural drainage lines into our creeks, rivers and bays.
Project background
In 2018, the developer of Thornhill Park Estate began works to establish a retarding basin. After this was handed over to Melbourne Water to manage, it was determined that a drainage channel was needed north of the Western Freeway. The new channel helps direct stormwater towards nearby wetlands, ensuring water levels in the retarding basin are stable and consistent.
Landscaping works were deferred until the channel was built. This enabled water levels to be lowered so that civil works could be completed and plants could establish themselves effectively.
What the works involved
We began landscaping works in early 2025. These were completed in two stages:
- ‘Hard’ landscaping, including:
- outdoor fitness equipment
- viewing platform
- boardwalk and paved areas.
- ‘Soft’ landscaping, which included planting over 110,000 plants.
From April 2026, we are undertaking further soil preparation and planting. This is due to be completed by mid-2026.
Project location
The retarding basin is located near Paynes Road and the Western Freeway. It can be accessed from Wingfield Drive and Gilfillan Circuit in Thornhill Park.
