What is wrong with the existing dam and why can’t it stay?
Development Victoria originally looked at delivering the housing development around the dam as this would provide the best protection to the dam’s existing habitat. Unfortunately, once the dam was assessed by expert hydrologists, it was found that:
- The dam is structurally unsound with leaks and cracks in the dam wall detected.
- The banks are too steep. Waterbodies in residential areas are required to have gently sloping banks so if someone was to fall in, they could safely stand and make their way out. This is not the case with the Knoxfield dam. If someone was to fall in, it could be a potentially very dangerous.
- The dam does not meet the stormwater management requirements for the site.
It is important to note that we have considered all options in making the decision to create a new wetland. Any rectification of the dam’s significant structural issues would still result in significant draining of the dam and completing earthworks which would result in the subsequent loss of the dam’s habitat.
Given there is no future scenario where the dam habitat can be protected, Development Victoria has designed a new wetland that meets safety criteria for the dam’s steep banks, meets the design requirements for flood and storm water management and provides better nesting and breeding habitat for water birds including the Blue-billed Duck.
Why can’t you leave the dam for Blue-billed Ducks to breed?
Due to its age and original construction the dam is structurally unsound, with leaks and cracks in the dam wall detected. While this can be repaired in the short term, fixing the structural issues long term would require the dam to be drained which would significantly impact the dam’s existing habitat, including the loss of Blue-billed Duck nesting habitat.
The repairs to the structural problems with the dam will have to occur regardless of the future use of the site meaning the loss of habitat is ultimately unavoidable.
Given there is no future scenario where the dam habitat can be protected, Development Victoria designed a new wetland that provides better nesting habitat for water birds including the Blue-billed Duck and meets the safety and flood and stormwater management requirements for the site.
How will you protect wildlife during construction?
The wetland will be delivered in stages to ensure there is always a significant body of water on site for the Blue-billed Duck and other species.
During the staged construction, we will continue to monitor the behaviour of the Blue-billed Duck and other species. Decommissioning of the existing dam will commence after we have seen sufficient establishment to support the existing water bird species. This will be guided by our expert ecologist. Development Victoria will take all steps to ensure there is always a significant body of water on site for the Blue-billed Duck and other species.
Are you moving the dam simply to make room to develop more townhouses?
No. When Development Victoria first acquired the site, they looked at designing the housing development around the dam to provide the best protection to the dams existing habitat and be the most cost effective.
However, due to the structural issues with the dam, we had to design a new wetland that meets safety criteria for the slopes of the dam’s banks, meets the design requirements for flood and stormwater management and provides better nesting habitat for water birds including the Blue-billed Duck.
How are the community’s views represented in the draft Masterplan and wetland proposal?
Feedback received in 2019 was compiled and considered along with a range of technical and environmental investigations to develop a draft Masterplan for the site. The draft Masterplan will be used to guide how the new neighbourhood will be developed in the future.
Development Victoria has also met with key community groups over a number of years to listen to their views and desires to maintain the existing dam on the site. Throughout this period, we have endeavoured to explain the structural issues with the dam and the limitations this placed on saving the Blue-billed Duck habitat.
We understand the importance of this site to the community which has become home to a range of vulnerable species. It is our continued commitment to work with the local community on the final design of the wetland and public areas so it can meet the community’s desires for a healthy, vibrant wetland that can support a range of wildlife, including the Blue-billed Duck.
WHERE CAN I FIND OUT MORE?
You can find out more from the Development Victoria website here.
For more information and resources from Development Victoria’s newsletters and reports, you can visit here.