We are planning to upgrade Campbellfield retarding basin to ensure it continues to reduce flood risk for the community.
Campbellfield retarding basin plays a crucial role in managing stormwater in your local area. When heavy rain occurs, the retarding basin embankment holds back stormwater and slowly releases it downstream, reducing flood risk to residents and businesses.
What's happening and when
Aqua Metro Services is delivering these works on behalf of Melbourne Water. Work will be undertaken primarily on the embankment and the outlet of the retarding basin.
The upgrade involves:
- excavation of a trench along the embankment crest
- backfilling the trench with a new sand filter
- removal of trees and vegetation along the embankment
- installation of a filter trench around the outlet
- erosion control and earthworks along the southern end of the retarding basin
- revegetation after construction work
Tree removal is a standard practice on all retarding basin upgrade projects.
Once construction is complete, the grassed areas will be reinstated with topsoil and hydroseed. Hydroseed is a mixture of seed, water and mulch that produces grass growth at a much faster pace than regular seeding.
We are working with Moreland City Council to develop a reinstatement plan for planting trees elsewhere.
Timing of works
Works are schedule to begin in late March 2018 and will take up to four months to complete.
Works will place Monday to Friday 7am to 6pm and Saturday from 7am to 1pm. Outside of these times quiet work may take place.
Location of works
The Campbellfield retarding basin is located on Sages Road in Glenroy. The works will be conducted within the closed site on the retarding basin embankment, which is highlighted on the map below.
Construction crews and traffic will access the site via Sages Road. The work area will be contained to the embankment located within the closed retarding basin.
We’ll continue to work with local residents to inform them of the works schedule and any associated impacts that may take place.
What to expect
This is a closed site and we expect there should be minimal impact to the community and residents. We anticipate our neighbours may notice:
- large trucks and machinery working in the basin
- site shed and worker amenities installed in the basin
- increase in traffic in the area along Sages road
- removal of trees and vegetation from the embankment
- some noise, dust and vibration from construction activities, mitigation measure will be in place
- increased traffic through Sages Road
Working with the community
We’re committed to reducing the impact of construction works on the local community.
We will be speaking with local businesses and residents in early 2018 about the upcoming works.
We’ll continue to keep you updated as the project progresses.
Why we are doing these works
We have over 200 retarding basins that we regularly assess for risks and conduct maintenance and upgrade works as necessary.
We have been directed by the Minister for Water to ensure all of retarding basins comply with the Australian National Committee on Large Dams (ANCOLD) guidelines. The ANCOLD guidelines represent the best Australian and international engineering practice in the safe design, management and operation of dams.
Campbellfield Creek retarding basin has recently been assessed against the ANCOLD guidelines. The assessment has shown that upgrade works are necessary to ensure the retarding basin continues to reduce flood risk and operate safely for the community. The upgrade is occurring to further lower the risk profile and to ensure the risk is as low as reasonably practicable.
Under the ANCOLD guidelines trees must be removed from the whole length of the embankment to ensure its integrity and provide the best possible level of dam safety. In the past, it was common practice to have trees on retarding basin embankments. However, as understanding of dam engineering has improved it has become evident that trees significantly weaken embankments and increase the risk of failure in a high rainfall event.
Campbellfield Creek retarding basin will require approximately 80 trees to be removed as part of this safety upgrade project.
During a large rain event, trees on the embankment increase the chances of embankment failure. They do this by increasing the risk of:
- soil erosion and displacement – when a tree dies its roots decompose and offer open water passages through the embankment
- trees uprooting and taking part of the embankment with them
- water speeding up around tree trunks and causing accelerated embankment erosion
We understand the emotional and environmental importance of trees to the local community and are committed to working closely with you to develop an appropriate plan for reinstatement of trees elsewhere.
We are committed to providing regular updates on the project to keep the community informed.
If you do have any questions or feedback, please get in touch: