Introduction
The Gippsland Region Sustainable Water Strategy aims to identify and understand potential challenges for water management and opportunities to secure our water resources for the next 50 years. It seeks to improve our knowledge of these issues and shape policies and actions that will ensure sustainable water supply and management over that period.
The Draft Strategy provides an opportunity for the community to help determine what needs to be done to share water between agriculture, towns, industry and the environment, and improve water resource management in Gippsland. The Strategy aims to:
- ensure secure water supplies for towns and industry
- encourage economically viable and sustainable agriculture
- support tourism and recreation
- protect and improve the health of rivers, wetlands, estuaries and aquifers.
The Gippsland Region
The Gippsland Region, as considered in this Draft Strategy, spans the area south of the Great Dividing Range in Victoria from the Latrobe River catchment and the Strezelecki Ranges to the New South Wales border in the east (see Figure E1). Larger urban centres include Warragul, Traralgon, Wonthaggi, Sale and Bairnsdale. The region supports important industries including electricity production, dairy, forestry, fisheries and tourism. The Macalister Irrigation District is the largest irrigation area in southern Victoria.
The region boasts the largest estuarine lagoon system in Australia – the Gippsland Lakes – which is a major tourism destination. Gippsland also has some of Victoria’s best preserved natural environment including forested catchment areas and heritage-listed rivers that are still in their natural condition. It also contains Victoria’s largest free-flowing river, the Mitchell River, with upper reaches of high environmental significance.
Gippsland comprises seven major river basins: East Gippsland, Snowy, Tambo, Mitchell, Thomson, Latrobe and South Gippsland. The Latrobe, Thomson, Macalister, Tambo and Mitchell river basins flow into the Gippsland Lakes while the catchments in South Gippsland and Far East Gippsland flow through local estuaries to the sea.
The Draft Strategy considers:
- Part One – threats to water availability
- Part Two – policies and actions to respond to the challenges and opportunities
- Part Three – how these policies and actions will be applied to address the challenges and opportunities for the sub-regions:
-
- South Gippsland
- Catchments of the Gippsland Lakes
- Far East Gippsland.
Figure E1 The Gippsland Region
Threats to water availability for users and the environment
Gippsland is one of the wettest areas in Victoria and historically has experienced relatively reliable rainfall. However, over the past 13 years there has been a significant decline in annual average rainfall across Gippsland, as well as the rest of south-eastern Australia as shown in Figure E2. This has lead to the lowest streamflows on record being observed in many waterways across Gippsland over this period (see Table E1), with average annual streamflows dropping to almost half of what they were previously.
The unprecedented dry conditions have required urgent actions to maintain supplies in some urban water supply systems, as well as impacting on dryland farmers, irrigators and the health of Gippsland’s waterways.
Figure E2 Rainfall over recent years (1 January 1997 - 31 May 2010) compared to the long-term average
| Waterway | Impact experienced since 1997a |
|---|---|
| South Gippslandb | -41% |
| Latrobe | -43% |
| Thomson | -43% |
| Macalister | -40% |
| Avon | -55% |
| Mitchell | -36% |
| Tambo and Nicholson | -44% |
| Snowyc | -49% |
| Other catchments in East Gippslandb | -33% |
Notes:
a- Reduction of average annual inflows when comparing pre-July 1997 average inflows to post-July 1997 inflows. Reductions shown are calculated to 2008 except for the Snowy and Mitchell Rivers which are calculated to 2009.
b- Calculated based on some of the larger river systems within these catchments.
c- Calculated from gauged data at Jarrahmond.
While Gippsland has faced extended dry periods before (eg. 1936-1945), the recent dry period is different from earlier droughts. Differences include a reduction in the very wet years that historically break up any long dry period, and a change in seasonal rainfall, including a reduction of about 25 per cent in autumn rainfall. Current climate research indicates these changes are likely to be at least partly linked to global warming, although only time will tell before we can say with any certainty whether we are experiencing an extended drought or a major change in our climate.
Whether the past 13 years are a result of climate change or drought, we can make the impacts of extended dry periods less catastrophic for water users. Fortunately the rainfall over the first half of 2010 has been close to the long-term average for Gippsland, however rainfall over the coming few months and years will reveal whether there has been a shift back to more normal rainfall patterns, or whether the dry conditions continue. The dry conditions of the past 13 years has reduced the amount of water stored in aquifers and many surface water storages, which would take months or years to recover even with a return to more normal rainfall patterns.
In addition to risks posed by a drier climate in the future, changes in the types of land use across Gippsland’s catchments could affect the amount of run-off. More 'lifestyle' farms may mean a growth in the number of farm dams, and potential increases in plantations and forest cover may also reduce downstream water availability. We need to understand more about the cumulative impact of these activities and how to manage them to protect water users and the environment.
Responding to future drought and the potential impacts of climate change
This Draft Strategy outlines policies and actions to provide water users, water corporations, environmental managers and communities with the tools and information required to adapt to changing water availability. Decisions on how the water that is still available in Gippsland should be managed is a key strategic issue: we need to be prepared for a future with less water; with the ability to cope with prolonged droughts or potential climate change; but we also want to be ready to capture the economic and environmental benefits of making the best, sustainable use of available resources if we return to more normal conditions.