As part of the development of the Enlarged Cotter Dam (ECD) and Murrumbidgee to Googong Water Transfer Project (M2G), Icon Water was required to provide habitat as an offset (offset site) to compensate for vegetation and habitat losses arising from the construction activities associated with these two projects.
The M2G offset habitat of approximately 110 hectares, which borders the ACT managed Gigerline Nature Reserve, has been set aside for conservation due to its high biodiversity value; including Commonwealth, NSW and ACT listed Box-Gum Woodland, threatened flora and fauna species and/or threatened species habitat. Rocky outcrops are widespread throughout the study area and contain habitat for the Aprasia parapulchella (Pink-tailed Worm Lizard).
This Rosenberg’s Goanna (a threatened species) was sighted on the M2G Offsets property in March, 2015.
The Enlarged Cotter Dam Biodiversity Offsets Implementation Program (ECD BOIP) was implemented as a commitment against the conditions of approval for the construction of the ECD. The program covered over 400 hectares and is designed to rehabilitate and increase biodiversity in the fire damaged Cotter catchment.
The program saw the following activities carried out within the offset area;
- Weed control
- Willow removal along Paddys River
- Revegetation with endemic trees and shrubs
- Erosion and sediment control
- Annual monitoring and reporting
Conserving protected trees, species and habitats
As part of our role in delivering water and sewerage services to the residents of Canberra and Queanbeyan, Icon Water is committed to protect threatened species and ecological communities as well as conserving registered and regulated trees under the ACT’s Tree Protection Act 2005.
Conducting the sustainability scorecard in early project planning enables the generation of alternate routes or construction methodology if threatened species are located in the vicinity of the project.
Field investigations identify the presence of protected species important habitat such as nesting hollows in advance so that maintenance activities can minimise impacting on them.
Conserving our endangered native species
Our work in planning the Murrumbidgee to Googong Water Transfer (M2G) pipeline near Williamsdale identified the endangered Small Purple Pea (Swainsona recta) specimens along the proposed pipeline route. While the pipeline was micro-aligned to ensure no plants would be disturbed, we were keen to play an active role in protecting the beautiful and nationally endangered plant. With the assistance of the Australian National Botanic Gardens and other organisations, the pea was successfully propagated and around 70 plants were planted on the 110 hectare biodiversity offset site established by us to offset the construction of the M2G project. Icon Water continues to monitor these species to assess their long term success.
To help in the conservation of the endangered Macquarie Perch within the Enlarged Cotter Dam, Icon Water, together with key partners, designed and built a 7 kilometre artificial freshwater rock reef– a first of its kind.
“The rock reef is a significant example of the environmental responsibility ACTEW has embraced...I commend the partnership between ACTEW, the Australian National University, University of Canberra and the University of Sydney that has produced this important project”
Simon Corbell, Minister for the Environment and Sustainable Development.
Aerial view of artificial rock reefs before they were inundated
In addition to providing opportunities for fish conservation and enhancing the development of the fish species, the rock reef will assist with university research on these fish species and their habitat well into the future.
Recognised for its originality and ground-breaking design, this project received the Australian Water Association National Award for Program Innovation in 2013.
As part of our management and maintenance of assets we undertake routine weed management and pest eradication programs to remove relevant species in order to improve the recovery and conservation of native vegetation, protect our assets from the impacts of pest plants and animals and uphold the conservation values of the surrounding areas and reserves in which many assets are located.
Rehabilitating land disturbed by activities
Following the construction of the Enlarged Cotter Dam (ECD) and the Murrumbidgee to Googong Water Transfer Project (M2G), Icon Water rehabilitated over 80 hectares of land disturbed by the construction of these projects. Innovative techniques to sow native grasses and forbs were implemented on the M2G project whilst over 30,000 trees and shrubs were planted on both sites to rehabilitate the land disturbed during the construction process.
Icon Water sources water from the Murrumbidgee River, the Cotter River reservoirs and the Googong Reservoir to provide a water supply for treatment and distribution as drinking water. At all of these locations, Icon Water is required to ensure that the needs of the aquatic environment downstream of the dams (or the abstraction points on the Murrumbidgee River at Angle Crossing, and at the Cotter River and Murrumbidgee River confluence) are protected. This is done through the protection of environmental flows.
The protection of environmental flows is governed under Icon Water’s Licence to Take Water under the Water Resources Act 2007 and through Conditions of Approval for M2G and ECD. The volume and timing of environmental flows required are based on extensive research and monitoring of the aquatic ecology in the water supply catchments.
The Water Resources Act 2007, through the Environmental Flow Guidelines 2013, recognises the need to effectively distribute water between the environment and Canberra’s population. Hence, in dry times, water available for Canberra’s population is reduced (through Temporary Water Restrictions) and so are the volumes of environmental flows downstream of the dams and extraction points.