This year's watering priorities, which will guide the decisions of water managers across the basin, also sees an individual fish species make the list for the first time.
MDBA spokesman Colin Mues said watering priorities released each year take a basin-wide perspective to identify which areas and natural processes, such as fish and bird breeding, were in most need of receiving water in the next twelve months.
"We've named priorities that span the four big indicators of river system health—native plants, waterbirds, fish and how rivers connect with each other and the landscape—and tailored them to a dry scenario," Mr Mues said.
"With the declaration of El Nino conditions, we're expecting water managers to have less water to work with.
"This means it's more important than ever that we use available water strategically, to help to build and maintain resilience in the basin, so the system can withstand the dry times and bounce back when wetter times return.
"Creating and maintaining refuges so that animals can shelter, breed, feed and get away from predators is really important during extended dry periods."
Mr Mues said another priority on the list this year was for weir pool levels in the Murray system to be adjusted as well as water levels to be varied in the Lower Lakes, as efficient ways to deliver environmental benefits.
Environmental water managers would also need to look for opportunities to piggyback off natural flow events as they occurred, in order to make the most of the available water, Mr Mues said.
Commonwealth, state and local agencies have had successes with environmental watering over the past few years, and will refer to these priorities when planning their watering activities for the year ahead.
ENDS
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ADDITIONAL INFORMATION FOR MEDIA
Priorities for 2015–16
River flows and connectivity
- Basin-wide flow variability and longitudinal connectivity: Provide flow variability and connectivity within rivers to support refuge habitats.
- River Murray weir pool variation: Ensure a variable flow pattern and lateral connectivity through coordinated weir pool management in the River Murray from Euston to Blanchetown.
- Coorong, Lower Lakes and Murray Mouth: Improve water quality, fringing vegetation and native fish movement by varying the water levels in Lakes Alexandrina and Albert to maintain flows into the Coorong and Murray Mouth.
Native vegetation
- Basin-wide in-stream and riparian vegetation: Maintain and where possible improve the condition of in-stream riparian vegetation, through in-channel freshes (flows).
- Mid-Murrumbidgee Wetlands: Improve the condition of wetland vegetation communities in the mid-Murrumbidgee wetlands.
- Macquarie Marshes: Maintain semi-permanent wetland vegetation in core refuge areas in the Macquarie Marshes.
- Moira grass: Maintain the condition and range of Moira grass in Barmah–Millewa Forest by supplementing a natural event and extending the duration of inundation.
Waterbirds
- Basin-wide waterbird habitat and future population recovery: Improve the complexity and health of priority waterbird habitat to maintain species richness and aid future population recovery.
Native fish
- Basin-wide native fish habitat and movement: Maintain native fish populations by protecting and improving the condition of fish habitat and providing opportunities for movement.
- Silver perch: Contribute to the long-term recovery of silver perch by maintaining key populations, supporting recruitment and facilitating movement and dispersal.
- Northern Basin fish refuges: Protect native fish populations and in-stream habitats, particularly drought refuges, in the northern basin.
FREQUENTLY ASKED QUESTIONS
Why these priorities and how are they used?
These features of the basin were identified as having the greatest need for watering in the coming year and as benefiting most from available water.
The basin-wide priorities recognise that the system is interconnected and needs a whole-of-basin approach to water management. They complement the more local watering priorities identified by the states and local authorities.
Environmental water managers, like the state and Commonwealth environmental water holders, will need to consider the MDBA’s priorities throughout the year alongside more local priorities. They will be releasing their planning for the coming water year shortly.
Setting priorities on an annual basis allows us to use an adaptive approach to environmental watering. This means the priorities are updated each year and are based on the latest information about the environment's needs and the seasonal outlook.
What is environmental watering and why do we do it?
Environmental watering is about actively delivering water, or protecting natural flow, to rivers and wetlands in the basin at certain times of the year.
For the past century, the basin has been developed with a main focus on delivering water for irrigation. We have built storages to capture and store water to be used in dry periods, and water is delivered at times when it is most needed for towns and irrigation.
These changes mean that the natural flows that once reached floodplains and connected our rivers to our wetlands are now often captured and stored in dams. It also means that water is being delivered through the system in regular patterns at times that suits production, and not necessarily in a more natural, variable way that most benefits and supports the environment and natural processes, such as bird breeding.
Over recent decades, we have come to recognise that changed flow patterns have meant some parts of the basin no longer receive enough water, don’t receive flows for long enough, or don’t receive water at the right time of year.
Environmental watering, which has been done very successfully for many years in some parts of the basin, is a way we can get water to important sites in the basin when it is of the most benefit to the environment.
It is important to point out that environmental watering isn’t about returning the basin to a pre-development state. It’s about building resilience by getting flows to environmental areas at the right time of year for sufficient periods of time.
A common misconception is that environmental watering is just done in drier times. In dry periods environmental water is critical for drought refuges however, environmental watering is also needed in average to wet years, when flows would have once naturally watered environmental sites but are now captured and stored in dams or diverted.
How do you decide what the priorities will be?
When deciding on priorities, we look at past and current conditions, forecasts, water availability and past watering. Then we assess what basin environments need, what might deliver the best results, and look at how it fits with the environmental outcomes decided in the over-arching basin-wide watering strategy.
We also consult with state agencies and take their priorities into account, ensuring a top down and bottom up approach to planning.
In the months before these priorities, we also release a watering outlook as an early indication of our thinking for watering opportunities in the coming year, for yet another round of feedback.
Some priorities are listed for consecutive years if the MDBA feels there are more environmental outcomes that could be achieved or if the watering was not able to be done to the extent recommended in the previous year.
How does environmental watering respond to drought conditions and El Nino?
Each year we look carefully at past and present climate conditions, predicted rainfall, soil moisture and water storage. All these things and more give us a scenario for how much water will be available for managers to work with.
This year in the northern basin we're predicting a dry scenario, so the focus will be on the resilience of environmental assets and making sure they can function at the basic level.
We predict conditions in the southern basin will be moderate to dry, so the focus will be on maintaining the health of environmental assets and building resilience.
In dry conditions, the environment gets less water so we work out which locations need water in order to keep some core refuges for birds, fish and other animals to give them respite. Without these refuge areas, in drought conditions there could be irretrievable damage to native plants and animals.
The priorities are made to be flexible. If the conditions get worse or better, we can adapt them to the amount of water available.
This year we have identified four basin-wide priorities for native vegetation, native fish, waterbirds and connectivity. These allow for opportunistic watering that can piggyback off natural flow events.
Watering in dry times benefits farmers, industry and towns. It helps us keep rivers connected and improves water quality. Without watering, it may be harder to deliver irrigator entitlements and good quality water.