Environmental issues


Water gallery

Landholders assist with environmental water deliveries

Landholders are playing a central role in the delivery of environmental water to Yarrein Creek, near Moulamein.

Following a request from the community and a meeting with landholders, the NSW Office of Environment and Heritage (OEH) committed up to 3000 megalitres of environmental water to the project.

Senior Environmental Water Manager Paul Childs said the water was being delivered via Murray Irrigation infrastructure with assistance from landholders throughout the event.

‘Changes to the Yarrein Creek’s hydrology have led to a range of issues including salinity and declining habitat values for birds, frogs and fish,’ Mr Childs said.

‘The creek once connected the Edward and Niemur rivers during times of high water flow.

‘The creek hasn’t seen an end-of-river flow since the 1970s,’ he said.

In partnership with local landholders, the OEH is running a trial watering event in the upper and mid sections of the Yarrein Creek.

‘The aim of the flow is to reinstate a wetting phase and ‘prime’ the system in anticipation of an additional flow - pending available water - in 2015/16,’ Mr Childs said.

‘The flow will inundate about 30 per cent of the creek and allow water managers to gain a better understanding of how water moves through the system and the volume of water that can be carried.

Environmental water is being delivered via Murray Irrigation’s Northern, Northern 7, Northern 8 and Mallan escapes.

Flows will be monitored closely to minimise the chance of interrupting access for nearby landholders.

‘The OEH will monitor flow movement and vegetation response with assistance from landholders and Murray Irrigation,’ Mr Childs said.

Baby boom follows environmental watering at Yanga National Park

A new generation of waterbirds will soon take flight from nesting sites at Yanga National Park, near Balranald.

Hundreds of egrets, night herons and cormorants have taken up residence in the park, establishing two rookeries where they have built their nests and are now raising their young.

Environmental water has created ideal conditions for the breeding event – a first for internationally recognised great egrets in the park since 2011.

The NSW Office of Environment and Heritage is managing the event which will see up to 73,000 megalitres of Commonwealth environmental water and 6000 megalitres of OEH water delivered to the site.

To read more about the baby boom in progress, see the full media release Baby boom in Yanga wetlands.

Nature close-up - take a tag-along tour of Yanga National Park

Yanga National Park is the place to be these school holidays with tours taking visitors into the far reaches of this dynamic ecosystem.

Visitors to Yanga National Park can join one of three tag-along tours hosted by the National Parks and Wildlife Service on Wednesday 8 April, Friday 10 April or Thursday 16 April.

These all-day tours begin at 9.30am with a cost of $20 per vehicle and take in areas of the park not normally accessible to the public.

Bookings can be made through the park office on (03) 5020 1764.

For more information read the full media release Wet, wild school holidays adventures at Yanga

Yarradda Lagoon on the road to recovery

Fish, frogs, turtles, trees and birds will all benefit from environmental watering at Yarradda Lagoon, near Darlington Point.

Work is underway to restore the health of the lagoon that was hit hard by the millennium drought.

Over the past few months, neighbouring landholders have managed the delivery of environmental water to the lagoon, in conjunction with the NSW Office of Environment and Heritage (OEH) and the Commonwealth Environmental Water Holder.

See the full media release Yarradda Lagoon Restoration a Collaborative Effort

Understanding 'return flows'

The NSW Office of Environment and Heritage is managing a series of ‘return flows’ in the North Redbank wetlands system. The flows are being carried out in conjunction with the Commonwealth Environmental Water Holder and Charles Sturt University.

What is a return flow?
Water from wetlands and floodplains is rich in nutrients, zooplankton, fish larvae and micro-invertebrates. When this water makes its way from the wetland or floodplain back into the river channel it is known as a ‘return flow’.

Return flows have become less common as demand for water increases. By monitoring  planned flows, water managers can learn more about the role they play in the health of the river for all water users.

Why are return flows important ?
Return flows restore the natural connectivity between the floodplain and river. The nutrient-rich waters become part of the food web, feeding fish, yabbies and other river animals.

Why is research important?
By understanding the benefits of return flows, water managers can target specific objectives with the timing and duration of future environmental watering events.

Who is conducting the research?
Scientists from Charles Sturt University (CSU) are funded by the Commonwealth Environmental Water Office (CEWO) to monitor conditions and ecological responses.

Are there any risks involved?
To avoid any adverse impacts on the river, wetland water is assessed prior to and during release and modelling is undertaken to identify release volumes.

Findings to date:

Levels of aquatic micro-invertebrates in the wetlands can be up to 10 times higher than the river. This makes the transfer of water important for feeding young native fish.

Fire and rain in the Lower Gwydir wetlands

It took less than a month for a landscape devastated by fire to show signs of recovery.

Fire blackened wetland in Lower Gwydir.

Marsh club rush in the Lower Gwydir wetlands one week after fire. Photo P Berney.

What made the difference?


In March of 2014, a lightning strike is thought to have ignited a blaze which swept through the Lower Gwydir wetlands in north western NSW. The fire ravaged 1600 hectares of wetland vegetation including stands of endangered Marsh Club Rush.

After three years of significant rainfall and river inflows, a hot, dry summer had left the wetland with a significant combustible fuel load.

One lightning strike was all it took to turn the landscape to ash.

It was a setback for staff from the NSW Office of Environment and Heritage (OEH) who had managed the recovery of the wetland from an impoverished condition after the drought, back to a healthy and resilient ecosystem.

But nature was on their side.

In the week following the blaze, the first substantial rainfall event of the season took place across the wetlands and Gwydir floodplain.

Senior Wetlands Conservation Officer Daryl Albertson said the rain extinguished the last of the smouldering fires and, coupled with small inflows, wet and refilled the soil profile, down to the root zone.

'A team comprising staff from OEH and the National Parks and Wildlife Service was assembled to determine the best course of action,' Mr Albertson said.

'In the second week of April – less than a month after the fire – the team visited the site and were amazed by the recovery that had already occurred.

'Wetlands plant specialist Peter Berney from NPWS reported that the sedge communities had bounced back rapidly, to the extent that some of the spike rush were flowering.

'The Marsh club rush (Bolboschoenus) were doing well with stands inundated to between five and 15 centimetres.'

In the nearby Coolabah woodlands, the groundcover had completely re-established with conditions favourable for further germination.

A flush of green growth follows fire and flooding in the Lower Gwydir wetlands.

Marsh club rush three weeks after fire and flooding. Photo P Berney.

The initial loss of vegetation had paved the way for water to move through the landscape over the course of days rather than weeks as had previously been the case.

Mr Albertson said overland flows had travelled through the nature reserve and into the adjoining property of Wondoona, filling the Wondoona waterhole.

'In doing so, the event demonstrated the absence of any man-made obstruction to water movement on the reserve or in the watercourses of the Lower Gwydir,' he said.

'Therefore, natural wetland vegetation is the major influence on flow passage through the nature reserve wetlands.'

In the months since the fire, the Lower Gwydir wetlands have continued to show remarkable improvements on their road to recovery.

Native sedges continue to respond positively, given the late season rainfall, while other wetland plants and birdlife have also returned to the area.

OEH’s role in managing the ongoing recovery at the site includes the planned delivery of water to ensure good inundation across the burnt areas and to continually monitor the site recovery, driven by strategic watering over time.

During the coming watering year, the OEH is aiming to achieve at least five to six months of continuous wetland inundation across a large portion of the remaining Gingham and Lower Gwydir wetland areas.

Deliveries have commenced from reserves shared between the Environmental Contingency Allowance and Commonwealth.

'Research in other locations has shown that supporting burnt wetland systems with post watering programs has long term benefits for wetland communities,' Mr Albertson said.

'We continue to monitor the wetland response closely and hope to see similar, positive results in the Lower Gwydir wetlands.'

Frogs bounce back after environmental flows

The Southern Bell Frog is green with mottled brown markings.

The Southern Bell Frog has been found in wetlands in the Murray Valley
after environmental watering. Photo: D Hunter/OEH

Southern bell frogs have struck up a chorus at sites near Wakool and Murray Downs as environmental water creates ideal conditions for breeding.

As part of a targeted watering initiative, the NSW Office of Environment and Heritage is managing the delivery of flows to the sites using NSW Adaptive Environmental Water.

Between 15 and 20 southern bell frogs have been heard calling during recent monitoring at Cockran Creek near Wakool with at least six individuals detected at a private wetland near Murray Downs.

And landholders have played a critical role in delivering the water which has led to this remarkable response.

Read the full press release 'Endangered frogs putting on a show at wetlands across southern NSW'.

Feathered frenzy at Fivebough!

Birds fly over Tuckerbil Swamp after environmental watering.

Birds have flocked to the Fivebough and Tuckerbil swamps (pictured) after environmental watering. Photo: J Maguire/OEH

Thousands of birds have converged on the Fivebough and Tuckerbil swamps near Leeton, in south west NSW, for what could become the biggest waterbird gathering on the site in 20 years.

Brolgas, bitterns and terns have been spotted after environmental watering provided the perfect conditions for feeding, foraging and - in some cases - breeding.

The Office of Environment and Heritage (OEH) has allocated more than 600 megalitres of environmental water to the Ramsar-listed wetlands.

At dusk and dawn, thousands of birds can be seen in the skies above the swamps - a spectacle that is expected to continue into the New Year.

To learn more, see our media release 'Birds, birds, and more birds at Fivebough and Tuckerbil swamps'.

Photography exhibition extended

By popular demand . . . a photography exhibition celebrating a major waterbird breeding event in the Gwydir wetlands has been extended.

The exhibition entitled ‘Waterbirds Return as the Gwydir Floods’ is now open at the Macquarie Regional Library at Dubbo where it will remain until the end of the year. It will then move to The Roxy Theatre and Visitor Centre at Bingara for the months of January and February 2015.

It is hoped it will be transformed into a digital product hosted on YouTube and made available to National Parks offices across the state in time for World Wetlands Day on 2 February 2015.

The exhibition of framed, large format photographs has toured galleries across the north west region with positive feedback at every site.

Senior Wetlands Conservation Officer Daryl Albertson said the number of visitors passing through the exhibition had exceeded all expectations, especially at the recent NPWS Dorrigo Rainforest Centre.

'The show has really captured the imagination of visitors,' Mr Albertson said.

'People who have seen the exhibition have asked when and where they can go to see this special place for themselves.

'What began as a book of photographs for landholders has now grown into a real celebration of these magnificent wetlands,' he said.

The exhibition features the work of four photographers including Daryl Albertson and Jennifer Spencer from the OEH along with Joshua Smith from Narrabri and Paul Bayne of Armidale.

In the last few months, the exhibition has also coincided with a trial opening of the Gwydir Wetlands State Conservation Area, giving people the chance to see first-hand the response of these wetlands to environmental flows.

View the images on flickr

Research underway in the North Redbank wetland system

In the North Redbank wetland system, scientists have joined forces with water managers to better understand the benefits of environmental flows as they pass through the wetlands and return to the Murrumbidgee River.

Return flows carry nutrient rich water from the wetlands to the Murrumbidgee River.

Return flows are the subject of research being conducted in the North Redbank wetland system. Photo: James Maguire/OEH

The Office of Environment and Heritage (OEH) is managing the delivery of environmental flows to the North Redbank wetlands near Balranald with a series of ‘return flows’ to follow.

Monitoring is being conducted by OEH staff alongside scientists from Charles Sturt University (CSU) who are funded by the Commonwealth Environmental Water Office (CEWO).

Senior Environmental Water Manager James Maguire said the project was designed to replicate the natural connectivity between the river and floodplain.

'We’re looking at the potential benefits of returning this highly productive water to the main Murrumbidgee River channel,' Mr Maguire said.

'Water from the warm, shallow swamps is brimming with zooplankton, fish larvae and macro invertebrates.

'When it’s returned to the river system it becomes part of the food web, feeding fish, yabbies and other river animals.

'By monitoring these return flows, we hope to inform the management of future watering events,' he said.

Return flows from the North Redbank swamps will be pulsed several times over the course of a month for several months.

'Scientists from CSU will work alongside OEH staff to monitor the flows and their effects,' Mr Maguire said.

'The results will help to determine timing, duration and future management of return flows.

'In the long term, the results will guide planned investment in new infrastructure such as fish-friendly water regulators that allow native fish passage.'

Dr Skye Wassens from CSU is co-ordinating the team of scientists monitoring the event.

Dr Wassens’ work is part of a collaborative effort to share the knowledge and expertise of individuals and organisations with an interest in environmental water across the Murray Darling Basin.

'The CSU team hopes to apply the lessons learned from the North Redbank return flows to other lower Murrumbidgee floodplain events,' Dr Wassens said.

'The monitoring is aimed at determining the scope of the effect we can achieve and the types of outcomes we can expect.

'Planning for return flows is determined by the ecological outcomes we hope to achieve.

'If, for example, our goal is to allow fish spawned on the floodplain to return to the river, then our monitoring results may enable us to plan for that.

'The effects could vary greatly depending on the timing of the return flows.

'For example, we may be able to target a nutrient peak in the river to coincide with the presence of larval cod.

'By starting these return flow pulses in spring, while the weather is still quite cool, we expect to reduce the nutrient load and minimise the risk of later hypoxic black-water occurrences.'

The results of the study will be used by the OEH and other relevant authorities to determine environmental water management goals and the best methods for achieving their objectives.

The North Redbank wetlands have been the recipient of environmental water over a number of years.

This year, the OEH has allocated 25,000 megalitres of Environmental Water Allowance (EWA) to the project with a further 20,000 megalitres from the CEWO.

This year, with the watering occurring earlier than last, the OEH is also hoping to trigger a significant waterbird breeding event in an historical rookery site within the wetland system.

Native fish set to benefit from Burrendong Dam's cold water curtain

Native fish will be among the beneficiaries of a new multi-million dollar cold water curtain at Burrendong Dam.

Members of the Environmental Flows Reference Group inspect the cold water curtain at Burrendong Dam.

Members of the Environmental Flows Reference Group inspect the cold water curtain at Burrendong Dam. Photo: Tim Hosking/OEH

The flexible curtain has been constructed around the intake tower to allow warmer, oxygen-rich surface water to be released downstream.

And the benefits are expected to flow for the whole river system.

The NSW Office of Environment and Heritage (OEH), with advice from the Macquarie-Cudgegong Environmental Flows Reference Group (EFRG), has already made use of this warmer surface water.

A ‘piggyback flow’ of 5000 megalitres was delivered to the eastern marshes in early September. The flow supplemented recent rainfall as well as stock and domestic flows.

A second flow of 30,000 megalitres was scheduled to reach the Macquarie Marshes in mid-October.

Senior Wetland and Rivers Conservation Officer Tim Hosking said the new curtain and warmer water would enhance the effects of these environmental flows and provide benefits to recreational river users as well.

'Anyone who has gone for a swim downstream of the dam will tell you how cold the water can be in the middle of summer,' Mr Hosking said.

'Until now, water for irrigation, town use and the environment has been released from a fixed intake point towards the bottom of the dam. In spring and summer that water can be quite cold and low in dissolved oxygen compared with conditions that would naturally occur in the river.

'The effect on river plants and animals – native fish in particular – has been significant.

'Research has shown that colder water impedes fish growth and reduces the length of their breeding season.

'Native fish wait for warmer water to breed which now doesn’t occur until later in spring and summer. By then, the European Carp have already spawned and competition for food is fierce, as carp compete at the very bottom of the food web by destructively eating algae and vegetation.

'Cold water also reduces the productivity of riparian and aquatic vegetation which further contributes to the challenges experienced by native fish,' he said.

Mr Hosking said the ecosystem response to the curtain may be muted in the first year or two, but the effects over the next three to five years should be significant.

'The whole ecosystem will benefit - from the macro-invertebrates to the yabbies, shrimp, platypuses, native fish, turtles and waterbirds,' Mr Hosking said.

The Burrendong Dam cold water curtain is now operational. Photo: T Hosking OEH

The Burrendong Dam cold water curtain is now operational. Photo: Tim Hosking/OEH

'With the right conditions, we hope to see improvements for native fish in the river reach between Burrendong and Narromine.

'From a social perspective, river users will notice warmer water when they go for a swim and over time, they’ll start to see more native plants and animals present in the river.'

The OEH is just one of several stakeholders keeping a close eye on the effects of Burrendong Dam’s new cold water curtain; with ongoing research being conducted by a team from the University of Technology Sydney, and additional funding allocated from the Commonwealth for NSW Department of Primary Industries (Fisheries) to undertake a system-wide fish survey.

In the meantime, staff from the OEH are looking forward to seeing the first effects of the season’s environmental flows, enhanced by warmer water via Burrendong Dam’s cold water curtain.

Fast facts:

  • The cold water curtain has been constructed at a cost of $3.4 million.
  • The flexible rubber curtain can be moved up and down with the level of the water behind the dam.
  • The initial concept design was funded by NSW Rivers Environmental Restoration Program, a Commonwealth program.
  • Further design and construction costs were shared equally between the NSW Government and State Water customers.
  • The environmental water release is a collaborative effort guided by an Environmental Flow Reference Group (EFRG) :
    • The EFRG meets several times per year to discuss environmental watering strategies, outcomes and planning. 
    • The Murray Darling Basin Authority has identified native fish outcomes as an annual priority in the Macquarie River under the Murray Darling Basin Plan.
    • Environmental flows in the Macquarie are managed by NSW OEH with key assistance from the Commonwealth Environmental Water Office (CEWO), State Water Corporation and the EFRG.

Paika Lake filled for the first time in a century

OEH and a small group of landholders have managed the delivery of environmental flows to Paika Lake, 20 kilometres north of Balranald. The 450 hectare lake had been kept dry due to a series of levees constructed more than a hundred years ago. Find out how this partnership helped more than 20,000 waterbirds, including three threatened species make the lake home.

Run time: 12:13 minutes

Creek systems flourish after years without water

The Jimaringle, Cockran and Gwynnes Creek systems between Wakool and Deniliquin are reaping the benefits of environmental flows, with vegetation flourishing and water birds and frogs enjoying the improved conditions. Download factsheet (13586Enviroflows.pdf 1506kb).

OEH has worked closely with local landholders to bring life back to the ailing 130 kilometre creek system, that travels through approximately 30 landholder properties located between the Edward and Murray Rivers.

To support the long term health of the environment, OEH is boosting natural water flows to deliver environmental water to the creek system. The environmental water flows began at the end of August 2012 and will continue into spring.

Environmental water Gwynnes Creek.

Environmental water at Gwynnes Creek. Sascha Healy/OEH

The health of the creek system suffered over the long dry period experienced in the last decade; Gwynnes Creek in particular has not had any substantial water flows for 40 years. So being able to leverage off the good wet conditions experienced in the last two years is a significant benefit for the system.

Monitoring inspections over the last two years in the Jimaringle and Cockran creeks have identified more than 20 waterbird species foraging in the creeks including egrets, cormorants and wood ducks.

Several different frog species have also been observed including pobblebonk, marsh and peron’s tree frogs. The painted burrowing frog was heard calling only days after the Gwynnes Creek environmental flows commenced.

The fringing River Red Gums, Black Box and Lignum and wetland vegetation such as Spike Rush and Duckweed have also shown improvement from the wet conditions.”

Up to 6,000 megalitres of environmental water in total from the NSW and Commonwealth government has been made available for delivery using Murray Irrigation Limited infrastructure.

Restoring the Tuppal Creek

In this video landholders talk about how red river gums and local wildlife are bouncing back with the help of environmental water delivered by OEH in 2012.

Cockran, Jimaringle and Gwynnes Creek Systems

This video shows how local irrigation infrastructure and teamwork have delivered environmental water to sections of the Murray Valley for the first time in 40 years with great results for plants and animals.

Extra water helps fish in the Edward-Wakool river system

Dissolved oxygen levels are now being boosted in this popular fishing river system thanks to extra environmental water deliveries being coordinated by OEH.

Edward Escape - environmental water release into Edward-Wakool river system

Edward Escape - environmental water release into
Edward-Wakool river system. Emma Wilson/OEH

Recent rainfall and flooding throughout the catchment had caused extra organic material to be deposited into the river, resulting in a ‘blackwater’ effect and lowering dissolved oxygen levels to below 2 milligrams per litre. This may have been causing native fish such as the Murray cod and yellow belly to experience severe stress and possible death.

It is expected that by 30 June 2012, up to 60 gigalitres of environmental water will have been released into the Edward-Wakool river system, since environmental releases commenced in early April.

There are promising signs that the poor quality blackwater is being diluted and better quality habitat created for native fish and other aquatic fauna.The Edward River at Moulamein recently registered healthier oxygen levels of around four milligrams per litre and there have been very few reports of fish kills to NSW Fisheries and the Murray- Darling Basin Authority.

This initiative has been delivered in partnership with the Commonwealth, State Water Corporation, Murray CMA, Forests NSW, NPWS, NSW Office of Water, Fisheries NSW, the river operators and the local community. All the environmental water for this event was sourced from the Commonwealth Environmental Water Holder.

Watering the world's largest river red gum reserves

Celebrating World Wetlands Day 2 February and 2011 International Year of Forests

Run time: 3.13 minutes
View video transcript
(ForestedWetlandsVideoTranscript.doc; 28 KB)

Lowbidgee Wetlands videos

Watch ABC TV News videos:

Birds from rejuvenated wetlands take flight (December 2010)
Water release revives Lowbidgee wetlands (September 2010)

April 2010

The Lowbidgee Wetlands near Balranald come to life after 8200 megalitres of NSW and Commonwealth environmental water was released via the North Redbank channel in March and April.

Birds flocked and vegetation flourished as the water spread across the floodplain on seven private properties: 'Murrundi', 'Springbank', 'Glen Avon', 'Auley', 'Moola', 'Riverleigh' and 'Baupie'. View video transcript (LowbidgeeWetlandsVideoTranscript.doc; 34 KB)

Largest environmental flow floods Yanga National Park

Red gums and reflections in very still waters, Yanga National Park

Red gums, Yanga NP. Photo: Paul Childs/OEH

Black and white photo of Piggery Lake showing trees in water

Piggery Lake, Yanga NP. Photo: J Maguire/OEH

Water flows to Tala Lake

Water flows to Tala Lake. Photo: James Maguire/OEH

Tala Lake, calm at sunset

Tala Lake. Photo: James Maguire/OEH

Find out more about Yanga National Park and environmental watering events.

Page last updated: 02 April 2015