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Werribee Catchment

Land Use

Urban

Rural

Forest

Water Quality Index

Very Good

Good

Fair

Poor

Very Poor

See the ‘Werribee Catchment’ page for a detailed description of the catchment.

Report Card for July 2012 – June 2013

The Report Card for the Werribee catchment has generated water quality index scores for the period July 2012 to June 2013. These scores are generated using a combination of standard indicators: nutrients, water clarity (turbidity), dissolved oxygen, salinity (conductivity), pH and metals.

These are sampled monthly across 15 sites as part of catchment monitoring programs.

The following section ‘Changes over time’ compares these annual index scores and indicators with the catchment's scores from 2000.

Results can also be compared to other catchments in the section below ‘Compared to other catchments’.

Site-specific details about indicators can be found via the site lists or can be accessed directly from the map.

Summary Table: The table below shows area-weighted distribution of site scores based on subcatchments. Scores are averaged in subcatchments with mutliple sites. See scoring method for more information.

Area Score
0%

Very Good
Near-natural high quality waterways

Forested upper catchments

18%

Good
Meets Victorian water quality standards

Forested upper catchment

45%

Fair
Some evidence of stress

Rural areas in the upper and mid-catchment

19%

Poor
Under considerable stress

Urban areas in the lower catchment

18%

Very Poor
Under severe stress

Smaller creeks that drain industrial areas in the lower catchment

The routine monthly monitoring across 15 sites accounts for 73% of the catchment. The remaining 27% of unmonitored catchment is mostly rural which typically scores as Fair for this region.

What does this mean?

Water quality scores varied across the landscape of the Werribee catchment, reflecting a variety of land uses.  Two sites in the upper reaches of the  Lerderderg River scored ‘Good’, whilst sites in the lower sections of the Werribee catchment scored ‘Fair’ to ‘Very Poor’. A number of sites draining urbanised sections of the catchment scored very poorly including Kororoit CreekLaverton Creek, Lollypop Creek, and Cherry MD. Rural sites in the upper and middle catchment typically rate as Fair. Nutrient runoff is the main threat to water quality in this part of the catchment and typically originate from rural sources such as agricultural runoff, stock damage to creek or river banks and septic tanks.

As waterways flow into the more populated and industrial regions of the lower catchment, water quality declines, which is largely due to increased metal concentrations originating from the urban catchment. Metals are commonly discovered in stormwater runoff from roads and industrial areas. Put more broadly, the increased stress on waterways in the lower catchment exists due to the sediment and pollution entering them from roads, industrial and agriculture areas.

Events

The Report Card's water quality index is based on monthly sampling which can mean short-lived environmental and weather events that can impact water quality are not always captured. This section highlights events for the 2012-13 reporting period.

In 2012-13 authorities worked with the Victorian Environmental Water Holder to deliver two environmental flows to the Werribee River and four environmental flows to Coimadai Creek (also known as Pyrites Creek) in Long Forest Nature Reserve. Environmental flows not only improve waterway habitat for aquatic species, they also boost recreational fishing, increase waterbird and wildlife numbers and improve the amenity of local parks for people to enjoy.

Bar chart showing WQI and indicator scores for Werribee Catchment Bar chart showing WQI and indicator scores for Werribee Catchment

werribee-werribeeriverestuary.jpg Werribee River Estuary. Source: EPA Victoria

WerribeeCliffsParksVic.jpg Werribee Cliffs. Source: Parks Victoria

Changes over time

In the Werribee catchment there have been water quality improvements since 2010-11 following the break of the drought. The amount of nutrients initially decreased with the breaking of the drought but has since gone back to pre-drought levels, possibly as a result of irrigation and agricultural practices returning to normal.

Salinity and dissolved oxygen have also improved post-drought due to increased flows in streams. Increased flows dilute salinity and improve dissolved oxygen by increasing volume and oxygen diffusion. The levels of metals found in the smaller waterways such as Lollypop Creek and Kororoit Creek are on average consistently Very Poor because of sustained industrial activity and road runoff.

The ‘Actions’ section below outlines projects and initiatives that will contribute toward addressing the issues outlined above.

Plot of WQI history for Werribee Catchment Plot of WQI history for Werribee Catchment

Actions

What's happened?

Driven by the key water quality issues identified for the Werribee catchment, major projects were implemented in the past five years to improve its waterway health in the catchments and included the following initiatives:

  • Kororoit Creek improvement - More than $1 million has been invested over the past five years to revegetate and upgrade the urban, downstream sections of Kororoit Creek.
  • Melbourne Water and Melton City Council hosted a community planting day at Caroline Springs to reconnect local residents with their creek to improve habitat and water quality for native animals.
  • Community groups in the Werribee catchment shared in $1.4 million worth of grants to support their environmental work to protect and improve waterways.
  • Partnership projects with local councils to build wetlands, raingardens and swales to treat stormwater runoff and remove pollutants that would otherwise end up in rivers and creeks including: Deer Park Shopping Village tree pits; Gloucester Reserve car park raingardens; raingardens at the Melton Library and Learning Hub; and water-sensitive urban design at Derrimut Road, Hoppers Crossing.
  • Melbourne Water planted 44 km of native vegetation and removed weeds from 93 km of waterways in the Werribee catchment.

For more information on projects and works in the Werribee catchment in 2012-13, please see the Waterways Local Updates.

What's planned?

A number of priority areas and actions have been identified in the Werribee catchment that will build on existing projects and initiatives. Future priority management actions include:

  • Protecting forested areas in the upstream catchments of Werribee, Lerderderg and Little River to maintain water quality and high macroinvertebrate (waterbug) diversity.
  • Managing urban runoff through improved sediment management on building sites and roads, particularly in new urban growth areas. Working with landholders to implement on-farm practices and on-ground works to reduce pollutants and runoff into waterways, and to remove stock access to waterways.
  • Continuing to deliver environmental flows to improve the water quality and habitats in Werribee waterways for the benefit of fish and local ecology.
  • Updated guidance for onsite wastewater management to reduce the impacts of stormwater pollutants and flows.
  • EPA hotspots investigations into high-risk waterways.

For more information about actions planned for the Werribee catchment to improve the health of rivers and creeks, please see the Healthy Waterways Strategy.

Compare to other Catchments

The following figures show a comparison of scores for each identified water quality indicator in the catchments and Port Phillip Bay.

Diagram of nutrient score history for catchments and bay

Diagram of oxygen score history for catchments and bay

Diagram of water clarity score history for catchments and bay

Diagram of salinity score history for catchments and bay

Diagram of score history for catchments and bay

Diagram of metals score history for catchments and bay

Program Partners

Department of Environment and Primary Industries Environmental Protection Agency Melbourne Water