How is Jacksons Creek protected from the impacts of recycled water?
Our licence to discharge from the EPA stipulates the volume of recycled water we can release to Jacksons Creek as well as the level of pollutants and nutrients in the recycled water when it enters the creek.
The licence limits are set through an extensive environmental risk assessment which is based on the background conditions of Jacksons Creek. The assessment considers both the positive and negative impacts of the discharge.
The licence also sets out the mixing zone for the recycled water release. A mixing zone is the area in which the water quality of the creek may be affected by the discharge and aquatic life may be impacted. The zone sets the area for water quality monitoring activities.
Western Water has not detected any adverse events in the creek as a result of our discharge. Nonetheless, the plant upgrade will see further improvement to the quality of recycled water produced at Gisborne and this will reduce the mixing zone – particularly for phosphorus and nitrogen. At the highest discharge volume rate, expected around 2035, the mixing zone would still be much less than it is today.
Because Jacksons Creek is subject to low flows, studies have found that the addition of recycled water can have an overall positive benefit on the waterway. This will be further investigated in the environmental risk assessment for the upgrade.
Working with stakeholders and the community
There are many other stakeholders caring for the health of Jacksons Creek. We work closely with Melbourne Water, the Port Philip and Westernport Catchment Management Authority, Southern Rural Water and Macedon Ranges Shire Council to ensure the best outcomes for Jacksons Creek. We also liaise with local environment groups to ensure their concerns and priorities are considered as we plan for the future.
- For more information about joining a local environment group and helping to care for Jacksons Creek, visit the Jacksons Creek EcoNetwork.
- For more information on grants for waterways projects, contact Melbourne Water who offer grants for public land projects, schools and community groups, and private landowners.
What biodiversity values are at the treatment plant?
While the land at the site has been significantly modified by original farming activity and, more recently, the treatment plant operations, the Gisborne RWP site is considered of moderate biodiversity value because of its location on Jacksons Creek.
It is located within the Victorian Volcanic Plain Bioregion and consists of patches of native vegetation and areas of exposed rock on its escarpment, as well as highly modified areas of exotic pastures and grass and planted vegetation.
The site is noted for its potential to support a range of waterbird species and the presence of some isolated large remnant eucalypts. Eels are known to live in the lagoons on site, returning to Jacksons Creek for breeding.
How does Western Water support the biodiversity of the treatment plant site and the creek?
Over many years, Western Water has been enhancing the biodiversity value of the site in partnership with Melbourne Water. Critical works have included removing exotic Willows and replanting the creek banks and nearby land with around 1500 native shrubs and trees. We will explore the potential to create more native habitat along the creek as part of the upgrade.
We also support studies of aquatic life in the creek - like fish and macroinvertebrate counts - and have worked with Melbourne University to better understand the benefits of recycled water for environmental flows for Jacksons Creek.