Department of Sustainability, Environment, Water, Population and Communities
The 2009-10 water year saw one of the worst droughts on record continue across much of the Murray-Darling Basin. Annual allocations of water against entitlements were low compared to long-term averages. However, the increased size of the Commonwealth environmental water holdings allowed an increase in the delivery of environmental water. In 2009-10, 154 gigalitres of Commonwealth environmental water was delivered, compared to 12.7 gigalitres in 2008-09.
Because of the drought conditions, the focus of 2009-10 watering was to avoid critical loss of threatened species, avoid irretrievable damage or catastrophic events, and maintain key refuges to allow recolonisation when conditions improve.
This outcomes report provides information on the early results of 2009-10 watering actions. While the full results of Commonwealth environmental watering will take some years to emerge, early monitoring indicates that environmental water has produced benefits, such as improved canopy cover and health in river red gums, as well as drought refuges for rare and endangered flora and fauna.
Environmental watering in 2009-10 also contributed to successful bird breeding events and helped to reduce the risk of acidification of Lake Albert, South Australia. In-stream flows following widespread rainfall across the northern Basin, contributed to connected system benefits. In some cases, floodwaters, which included a small amount of Commonwealth environmental water, filled flood-runners and anabranches.
Commonwealth environmental water is delivered with strong cooperation between governments and other organisations, catchment management authorities and local community groups. This approach takes advantage of local knowledge and on-ground capacity to manage water. It ensures the Commonwealth delivers targeted local benefits, while maintaining a Basin-wide perspective.
This report includes examples where environmental outcomes have been enhanced because of effective working relationships across the Basin. During 2009-10, Commonwealth environmental water was delivered with an additional 169 gigalitres from other sources including state delivery partners and The Living Murray program. We welcome water use proposals being brought forward by any group operating in the Basin and we will assess these against our published criteria.
Experience shows how water can be actively managed to reduce the risk of permanent damage to environmental assets during drought. Following significant rain in the spring of 2010, there will be major improvements in the availability of environmental water. Increasingly, there will be watering actions taken that achieve benefits across multiple sites, catchments and jurisdictions.
Watering actions that achieve connected system benefits are expected to become the major element of Commonwealth environmental water use. Larger volumes will enable the scope of environmental watering to expand and therefore protect or restore a broader range of connected environmental assets. The objective is to achieve maximum system benefits from the available water.
As the size and complexity of Commonwealth environmental watering actions increase, so too will the emphasis placed on monitoring, evaluation and reporting. All current use has monitoring arrangements in place and we will be seeking to further develop this approach in the coming year.
The considerable assistance provided over 2009-10 from state agencies, catchment management authorities and local groups is greatly appreciated. We look forward to building on these relationships in the future.