Sustainability Report 2006/07Protecting and improving biodiversity
With Melbourne entering its 11th year of drought, and climate change impacts being felt in changed rainfall patterns, higher temperatures, and more intense storms, the pressure is increasing on sites of high biodiversity value.
As a significant landholder and waterways manager within the Port Phillip and Westernport region, Melbourne Water plays a leading role in managing, protecting and improving biodiversity.
This region is home to a diverse range of important ecosystems, comprising extensive terrestrial and marine habitats and supporting more than 1860 species of native plants and 600 species of native animals. In these ecosystems 296 flora species and 128 fauna species are considered threatened.
The biodiversity values of the natural assets under our control vary widely. BioSites are sites of high biodiversity value and include internationally recognised wetlands, pristine mountain ash forests in protected water supply catchments, and the upper forested reaches of many waterways.
Victorian Biodiversity Strategy
The Victorian Biodiversity Strategy is an overarching strategy covering objectives related to the conservation and management of biodiversity. The Regional River Health Strategy, Melbourne Water’s Biodiversity Strategy and the Waterways Sites of Biodiversity Signi?cance Program provide a strategic approach for biodiversity management in areas under our management.
Our Biodiversity Strategy coordinates biodiversity management actions across all groups and natural assets, defines biodiversity values on Melbourne Water properties and sets priorities for management of these values.
Developing a detailed understanding of biodiversity values and collecting additional data on natural assets will help Melbourne Water demonstrate the extent to which effective biodiversity management contributes to an overall improvement of healthy ecosystems, vegetation communities and wildlife habitat.
Net Gain guidelines
Melbourne Water supports the Victorian Government’s native vegetation management framework. The framework introduced a ‘net gain’ goal as an outcome for native vegetation, where overall gains are greater than overall losses and individual losses are avoided where possible.
During 2007/08 we developed Melbourne Water’s draft Net Gain guidelines, which will help us deliver a net gain in native vegetation on land under our management through avoiding vegetation clearance, minimising impacts through design and management, and offsetting any losses.
These guidelines will play a key role in managing impacts of construction of the Sugarloaf Pipeline, which will connect the Melbourne water supply system with the Goulburn River.
Any loss of vegetation, habitat or biodiversity values associated with the pipeline construction will be offset through purchase and ongoing protection of land with high biodiversity value, such as land adjoining state or national parks.
First BushBroker trade
As a participant in the Victorian Government’s BushBroker Scheme, we traded native vegetation ‘credits’ to help meet the net gain target.
Native vegetation credits arise through a gain in the extent and quality of a specified area of native vegetation. This credit can then be traded with someone who has no choice but to destroy native vegetation.
In August, Melbourne Water sold some of the native vegetation credits as a test case. We had retained these credits with the transfer of freehold land around Devilbend Reservoir to the Government.
Green paper on climate change
Melbourne Water provided a detailed submission to the Victorian Government’s Green Paper, Land and Biodiversity in a Time of Climate Change, in June. The paper will set direction for Victorian Government policy and investment priorities in natural resource management, land health and biodiversity for the next 20 to 50 years.
Managing data
We continued work on our biodiversity condition and heritage system, which is designed to improve the collection, accuracy and management of biodiversity condition and heritage values of natural assets under Melbourne Water management.
Key aspects of the project this year involved determining how best to integrate the system into our wider IT Systems, and ways to make information available to external stakeholders such as government departments, councils, research agencies, catchment management authorities, developers and community groups.
This database provides detail on the diverse habitat types, plants and animals found on Melbourne Water property, and will contribute to the Geographical Information System layers managed by the Department of Sustainability and Environment.
Pest animal guidelines
Historical pest animal management guidelines have been reviewed and updated to create two pest animal documents – one for internal use and the other for contractors undertaking pest animal management activities on behalf of Melbourne Water.
These guidelines help reduce the risk of water quality issues associated with pest animal management, and ensure that these management programs are safe, humane, environmentally sound and economically feasible. Management actions aim to prevent new and emerging pests from having significant impacts on natural and productive resources.
The guidelines, which were finalised in late 2007, address pest animals such as foxes, rabbits, cats and dogs in protected catchments, reservoirs and land under our management.
BioSite surveys
Melbourne Water manages 36 sites with high biodiversity values through the Sites of Biodiversity Significance Program.
This program protects and improves the regional, state and national biodiversity values of these sites.
Consistent with the Biodiversity Strategy, we engaged natural environment consultants to undertake flora and fauna surveys to establish BioSite condition, and provide a baseline for future monitoring.
During 2007 we began a survey of the Cardinia Reservoir BioSite, based on the high risk of invasion by environmental weeds. The site has been divided into three stages with the second survey area completed in June 2008. Results will assist planning for weed management.
The survey involved a general fauna species survey, mapping and assessment of native vegetation, and mapping of weed invasions. Fauna surveys involved trapping, spotlighting, call playback and active searching during the day and night. Mapping and assessment of habitat was also undertaken.
Biodiversity conservation at the Western Treatment Plant
This program oversees conservation actions at the Western Treatment Plant to protect the extensive Ramsar-listed wetlands of international importance and other areas of high biodiversity significance.
Melbourne Water spent $586,000 this year on biodiversity conservation at the plant, including research to better understand the complex wetland and intertidal ecosystem, and on-ground management such as weed, fox and cat control, fencing and water depth manipulation on conservation ponds.
An important management aim is to boost the number of filter-feeding ducks using the wetlands. This involved drawing down water levels in Lake Borrie to allow placement of fallen timber to create perches and habitat, and encourage vegetation growth to support the birds’ invertebrate prey.
An audit and review of the program’s compliance with the Commonwealth Environment Protection and Biodiversity Conservation Act scored 64 out of a possible 66.
Drought response, conservation and research
Drought response planning for 18 wetlands supporting significant biodiversity values continued with the development of contingency plans for each site, and installation of depth gauges and monitoring to record and assess impacts.A population of the only Victorian wingless stonefly (Riekoperla darlingtoni) living in an ephemeral spring near the summit of Mt Donna Buang has declined drastically as a result of the drought. Work has begun to install a water tank to drip irrigate the bed of the spring and keep it damp – a condition critical for the survival of this species. This work is being done in collaboration with Parks Victoria.
The Western Treatment Plant Biodiversity Conservation Program may help protect the critically endangered orange-bellied parrot by improving waterbird habitat and restoring coastal saltmarsh.
Melbourne Water undertook a fish survey at the Western Treatment Plant’s Lake Borrie. The survey aims to protect biodiversity values, identify exotic and native fish species, and determine patterns and relationships to waterbird health.
Pipeline works
Melbourne Water and the Sugarloaf Pipeline project team have developed and adopted bio-security protocols for protecting the environment and biodiversity values on the project.
The protocols were developed in conjunction with the Department of Sustainability and Environment to work with landowners, land managers and others to prevent the transmission of plant and animal diseases as a result of works associated with the project.