Goulburn Broken Catchment Management Authority (CMA) The Living Murray project officer Lisa Duncan said environmental flows had provided a much-needed boost to the Moira grass plains, which form an important part of the ecological character of the Barmah Forest.
These flows mimicked the natural expected spring flow as well as piggybacking on high water deliveries for communities and agriculture at this time of the year.
‘‘Barmah Forest has the most extensive areas of Moira grass plains in Victoria and is an important breeding ground for ibis, ducks, cormorants, herons, spoonbills, crakes and rails,’’ Ms Duncan said.
‘‘Moira grass was hit hard during the millennium drought, declining to as little as five per cent of its former mapped area over the past 70 years due to a range of reasons, including grazing pressure from feral animals.
‘‘It can grow rapidly in the right conditions, but it needs deep and prolonged flooding to reach maximum growth and to reach the flowering stage of its life cycle.
‘‘Although there has been a good response this year from the three months we were watering, future water deliveries at the right time of the year will be vital for improving its long-term health and resilience,’’ Ms Duncan said.
About 20 per cent of the environmental water delivered across the Barmah Forest floodplain will remain in wetlands, while the rest will flow back into the Murray River.
The water returning to the Murray from the floodplain is rich in nutrients and provides the building blocks for the river’s food chain, from small waterbugs right up to large-bodied fish such as Murray cod and golden perch.
Barmah Forest, together with the adjoining Millewa Forest in NSW, forms the largest river red gum forest in the world, attracting thousands of visitors each year who camp, fish, swim and canoe.
The forest’s complex ecology is underpinned by the Murray River’s flooding regime, which is now being mimicked with Commonwealth and Victorian environmental water deliveries.
Ongoing monitoring at Barmah will examine how the recent water delivery affects water quality; bird, fish, frog and waterbug breeding and numbers; and other vegetation.
‘‘Monitoring helps us understand the effectiveness of the environmental flows and ‘tweak’ future timing and flows to get the best outcomes,’’ Ms Duncan said.
Environmental water is water specifically delivered to improve or maintain the health of rivers, floodplains and wetlands and the plants and animals that depend on them. Of the total amount of water entitlements stored in dams (such as Hume and Eildon), 20 per cent is used for the environment, 20 per cent for urban and industry and 60 per cent for irrigation.