Freshwater Mussels in the Murray Darling Basin

They are amazing biofilters, playing a crucial role in keeping rivers healthy. An abundant food source for First Nations Peoples, Freshwater Mussels are a critically important part of the web of life.

Once, they were second only to fish as the dominate life by weight in inland rivers.

The severe drought of 2017-2020, exacerbated the problems caused by decades of over extraction and mis-mangement of water in the Murray Darling Basin and the unthinkable happened – many rivers dried up completely. The Darling-Baaka was a series of small, green disconnected pools from Bourke to the Murray. The Macquarie-Wambuul was cut of at Warren, completely drying out the Macquarie Marshes and the Lower Macquaire.

Rightfully, the fish kills that resulted shocked and horrified the community. But the loss of an estimated 2.9 million Freshwater Mussels is a lesser known ecological catastrophe.

This post includes an article that appeared in The Conversation, and lower down a published study of the habitat and flow requirements of the Freshwater Mussels.

The internationally significant Macquarie Marshes is the only place in the northern Basin where remains of all three species of Freshwater Mussels that live in the basin were found. It is home to the biggest and oldest Freshwater Mussel remains that were found in the study, with one specimen measured at 137.2mm.

The presence of large, old Freshwater Mussels in places like the mid Darling-Baaka Rivers and the Macquarie Marshes proves that the natural wetting and drying patterns of these systems never included completely drying out, like they did in 2017-2020.

The Conversation – Academic rigour, journalistic flair

Professor Alan Lymbery – Jan 12th 2022

Freshwater mussels are dying suddenly and in the thousands, with each mass death event bringing these endangered molluscs closer to extinction. Tragically, these events rarely get noticed.

Read the full article here

Habitat and flow requirements of freshwater mussels in the northern Murray-Darling Basin.

Report to the Commonwealth Environmental Water Office
November 2020

Fran Sheldon and Nicole McCasker
Co-authors: Michelle Hobbs, Paul Humphries, Hugh Jones, Michael Klunzinger and Mark Kennard

Australian Rivers Institute, Griffith University

Institute of Land, Water and Society, Charles Sturt University

The authors respectfully acknowledge the Traditional Owners of the lands and waters of the Murray-Darling Basin, particularly those whose lands we walked on in this study, across the Darling, Barwon, Macquarie, Namoi, Gwydir and MacIntyre rivers. We acknowledge that Aboriginal peoples have cared for the rivers for millennia, and pay our respects to the Elders, past and present.

Executive Summary
Freshwater mussels are considered ecosystem engineers of rivers; they modify substrates through burrowing, mediate water quality through filtration, provide food and habitat for other organisms and play a significant role in the biogeochemical cycling of nutrients and are also seriously threatened globally. The rivers of the northern Murray-Darling Basin (MDB) are home to three species of freshwater mussel – the large ‘river mussels’ Alathyria jacksoni and Alathyria condola and the smaller ‘floodplain/billabong mussel’ Velesunio ambiguus. As sedentary, long-lived organisms, obtaining an understanding of the habitat requirements of resident freshwater mussels will provide insights into the natural hydrology of Australia’s inland rivers, and the potential role healthy populations of freshwater mussels could play in influencing water quality through biofiltration. This project was conceived in response to the extensive drought in the northern Murray-Darling Basin between 2017 and early 2020 and the reports of extensive mussel mortality. The specific aims were to review existing knowledge and identify knowledge gaps in relation to environmental water requirements, life history, physiological tolerances and habitat requirements and cultural significance of freshwater mussels in the Murray-Darling Basin, improve baseline understanding of distribution and structure of freshwater mussels in the Northern Basin and make recommendations for land and water management to protect freshwater mussel populations. This was achieved through a predictive analysis of mussel distribution, and analysis of the hydrological conditions during the drying event and a field survey to establish the extent of mussel mortality at sites across the northern Murray-Darling Basin……….

……… The combination of rapid and quantitative surveys used in this study suggest that the loss of mussel populations across the northern Murray-Darling Basin resulting from the drying conditions of 2017- 2019 is significant and widespread. This is a cause for concern given the longevity of mussel individuals and the poor evidence of widespread recent recruitment. Based on our analyses we make the following five (5) broad recommendations:

  • Recommendation 1: that further research needs to be undertaken to understand the biology of freshwater mussels in the northern Murray-Darling Basin, including their reproduction, recruitment, growth patterns and diets, as well as their role in the ecosystem of the northern Murray-Darling Basin Rivers – not least because, besides fish, they were historically the dominant animal by weight in these rivers.
  • Recommendation 2: that a focus be made on monitoring freshwater mussel recovery in both the short- and long-term. This should include an understanding of which fish species act as hosts and what conditions are required for successful recruitment and establishment of juveniles.
  • Recommendation 3: that the importance of low flows and refugial habitats, reaches and waterholes, be formally recognised for freshwater mussels in the northern Murray-Darling Basin and the flow requirements of freshwater mussels be incorporated into flow management plans.
  • Recommendation 4: that the role of refugial reaches and waterholes in the landscape persistence of mussels and fish be recognised and the flow required to maintain the integrity of these physical places in the channel network be understood and incorporated into flow management plans. This would require a basin- wide perspective of the Water Sharing Plans and Water Resource Plans to ensure the critical area of the Barwon-Darling River has adequate flows for long-term population survival.
  • Recommendation 5: that a specific Freshwater Mussel Recovery Plan be developed in consultation with the communities of the northern Murray-Darling Basin and this plan articulate with Fish Recovery Plans.

Proposed re-regulating dam set to destroy the best Murray Cod breeding spots in the Macquarie-Wambuul River

Media Release – Thursday 18th November 2021

The most important breeding sites for threatened Murray Cod in the Wambuul-Macquarie River have been identified in a report[1] released by the Commonwealth Government on Thursday, and they are right where the NSW Government plans to build an enormous new dam. 

All four of the monitoring sights near Gin Gin used for the study would be destroyed by the proposed Macquarie River re-regulating storage project, known locally as the Gin Gin dam.  

“This zone has previously been identified as a strong-hold for Murray cod recruitment within the Macquarie River” wrote the report’s author Jerom Stocks.

The report shows that water for the environment was used during Spring 2020 to provide stable flows to support Murray Cod nesting during the peak breeding period, and that water management by environmental water holders and community stakeholders was successful. [2]

However all the efforts and success of water for the environment would be for nothing should the NSW Governments plans to construct a new dam at Gin Gin go ahead.

“Murray Cod are listed as threatened, and are supposed to be protected by the Commonwealth Government. How can the NSW Government even consider building a destructive dam directly over their best breeding areas?” Said Mel Gray, Convenor of Healthy Rivers Dubbo. 

The Wambuul Macquarie River is a well know destination for recreational anglers chasing the iconic Murray Cod.

“Tourism is absolutely huge for the economy of this region, and any major infrastructure project that has a detrimental impact on tourism has the potential to be a disaster for our region.” said Councillor Stephen Lawrence, Mayor of Dubbo Region.

“To build a dam in the Mid-Macquarie River would be detrimantal to the breeding cycle and improvement of not only the Murray Cod, but Eeltail Catfish, Yellow Belly, Spangled Perch, Platypus, Turtles and everything.” Said Wayne Gilbert, President of the Inland Waterways Rejuvenation Association.

Media Contact

Mel Gray – Convenor Healthy Rivers Dubbo




Support the Gin Gin dam campaign here!

Don’t damn the Macquarie – No Gin Gin dam!

Support our work here

We are a group of people living in the Dubbo and Barwon electorates whose future relies on the long term sustainability of the Macquarie-Wambuul River and its connectivity with the Barwon Darling/Baaka River.

For many Nations including the Wiradjuri, Wongaibon and Wayilwan, the River and the Marshes are a lifeblood.

The Macquarie Marshes are internationally recognised wetlands of significance, a nesting site for thousands of migratory birds. Water from the Macquarie Valley provides vital connectivity to the Darling/Baaka, on average a 21% contribution.

But right now, the government in NSW is planning a disastrous dam at on the Macquarie at Gin Gin, downstream of Dubbo that would allow even more water to be sucked out of the river. There are already too many straws in the glass, as the mass fish kills in the Darling/Baaka and the Macquarie/Wambuul have shown. Instead of fixing the problem, the government seem to be making it worse!

Support our work here

This is your chance to partner with us! Together we can stop this project, which in time promises to terminate the river upstream of Warren, and leave the river bed and marshes dry.

The impact of this project on downstream communities and the environment would be catastrophic.

For this message to reach far and wide, we need to raise $4,000 for advertising in the newspapers, radio and other media in our region.

We have already succeeded in uniting the community to widespread objection to this disastrous dam and slow down the planning process.

With your help, we can once and for all send a message to politicians that we will not have our rivers turned into irrigation channels!

If you can’t donate, then please consider writing an email to your local NSW Member of Parliament, or to your local newspaper objecting to the disastrous river and marsh destroying Gin Gin dam.

Please share our campaign – THANK YOU FOR YOUR SUPPORT!

Floodplain Harvesting Inquiry


Select Committee on Floodplain Harvesting

HRD is grateful for the opportunity to contribute to the Select Committee on Floodplain Harvesting (the inquiry). We wish to express our gratitude to all Representatives who were involved in the two disallowance motions of the Floodplain Harvesting (FPH) Policy regulations in the Upper House, and the establishment of this inquiry.

HRD considers that FPH is an unlawful practice, and that Governments, Authorities and Agencies have turned a blind eye to the practice.

There are no legal levers between FPH policy and the water sharing priorities under the WMA (ss. 5(3) and 9(1)), which include water for ecosystem health and basic landholder rights (stock and domestic; native title rights).

The NSW Water Minister received internal legal advice that stated that on the balance of probabilities, taking water without an access licence is most likely unlawful. Building on-farm storages to house that illegally obtained water without the appropriate approvals would also be unlawful. This advice was withheld from the public until the Minister was urged in Parliament to release it.[1]

The irrigation industry has grown large and politically powerful in recent decades and in HRD’s view has too much influence on water policy at every level. The extent of this wealth and power has come from the illegal take of water.

In many parts of the world through history and to the present day the textile industry has used slavery to grow large and powerful. Only the erosion of social licence through community advocacy can bring about justice for the Environment, First Nations Peoples and the wider community.

HRD will argue in section 1 that: 

  • Volumes of FPH to be licenced must be brought under the Cap, and that the Cap should not stretch to accommodate FPH volumes. In the Macquarie Valley that means zero FPH.
  • The NSW Government is accommodating the irrigation industries arbitrary claim that environmental water in the Macquarie is ‘over recovered’. A claim HRD rejects outright and presents evidence to show that ‘over recovery’ is not a thing.
  • The draft Floodplain Management Plan 2018 must include clear process to ensure all illegal floodplain works are removed. The Floodplain Management Plan 2018 for the Macquarie is still not gazetted, which must happen ASAP.



Media Release – Govt Inquiry highlights worry over Gin Gin dam

Media Release

Wednesday 28th July 2021

Government Inquiry highlights worry over Gin Gin dam impacts

A parliamentary committee report looking at the controversial proposal to build a large ‘re-regulating’ dam in the Macquarie Rivers at Gin Gin was released today. The committee says they have ‘significant concerns about the potential negative ecological impacts’ of the proposal.

Community concern that WaterNSW won’t keep their hands off tributary inflows from below Burrendong dam is shared by the committee. The report says the lack of clarity regarding the use of tributary flows for water orders and how this will change as a result of the project is concerning.

“When this project was looked at as part of the Macquarie Priority Catchment Study, the plan was to take water from all sources. Now they say they won’t catch tributary inflows, but the economics of that doesn’t stack up. ” says Mel Gray, Convenor of Healthy Rivers Dubbo.

The committee heard that the best way to secure water for people and the environment is to improve the way water is managed in NSW.

The project poses a significant threat to remaining native fish populations in the Macquarie River. “The weir pool created by this dam proposal would destroy 32 km of habitat in and along the river. Population of threatened Murray Cod can’t bounce back after drought without habitat.” Said Ms Gray.

The report featured a warning from Professor Richard Kingsford that Australia is failing to meet its international obligations to protect Ramsar listed wetlands. Many waterbird communities are long-term decline as a result of historic water allocations and decreased river flows into major wetlands.

“There is certainly no environmental benefit of building that [Gin Gin] weir and there is a lot of risk in terms of downstream impacts, not just to the environment – the river – but also to the rural communities downstream.” Professor Kingsford was quoted as saying in the report.

Media Contact

Mel Gray

Convenor Healthy Rivers Dubbo


Report No 8 PC7 Rationale for, and impacts of, new dams and other water infrastructure in NSW – Part 2

Healthy Rivers Dubbo Public Meeting – June 2021

The Healthy Rivers Dubbo Alliance facilitated a public meeting about the proposed Gin Gin dam project on the Macquarie-Wambuul River.


Introduction (Mel Gray, facilitator) start to 7.30

Tony Lees (Trangie) 7.30 to 12.55

Professor Richard Kingsford (UNSW Centre for Ecosystem Science) 13.18 to 36.14

Garry Hall (Private Ramsar Wetland Manager) 36.30 to 49.20

Bev Smiles (President Inland Rivers Network) 49.40 to 106.35

Question and Answer session 107 to end

Dubbo Photo News 1/7/2021

The Daily Liberal 26/6/2021 Healthy Rivers Dubbo hosts Gin Gin Dam public meeting

Media coverage of Public Meeting about Gin Gin dam proposal

Listen to an interview on ABC Western Plains about the Gin Gin dam proposal and the Public Meeting listen from 5.43.

Read an article from the Dubbo Photo News 17/6/21 about the Public Meeting

Read an article from Dubbo’s Daily Liberal 14/6/21 about the Public Meeting

Media Release 11th June 2021

Professor Richard Kingsford will join an impressive line-up of speakers at a public meeting about the proposed Gin Gin re-regulating dam on the Macquarie River.The public meeting is to be held on Wednesday the 23rd June from 6.30pm at the Pastoral Hotel in Talbragar Street Dubbo.

Professor Kingsford’s expertise covers river ecology, water use in Australia, wetland ecology, waterbirds, river policy, and dam building effect.

Also speaking at the event will be:

  • Tony Lees from Trangie
  • Garry Hall, a private Ramsar Wetland Manager
  • and Beverley Smiles, President of the Inland Rivers Network

The controversial Gin Gin dam proposal drew sharp criticism from the NSW Government last year when the Deputy Secretary of Water said the plans “do not currently demonstrate value for money and an efficient, effective and prudent use of public funds.”[1]

The proposal is expected to reduce water downstream for unregulated irrigation, and have a serious impact on populations of native fish.

“The Gin Gin dam would be a massive $84 million subsidy to the irrigated cotton industry. Downstream irrigators, graziers and businesses that cater to recreational fishing in the valley would all take a huge financial hit.

“There have been increasing calls for Dugald Saunders MP and the NSW Nationals to release the business case to the public once it is complete. What are they trying to hide?” Asks Mel Gray, Convenor of Healthy Rivers Dubbo.

The public are encouraged to come along to the Pastoral Hotel with their questions about the impacts the proposal would have on the river, the marshes and all of the people and wildlife that rely on them.

For details about the event contact Mel Gray 0431 471 310, or email

Media Contact: Melissa Gray Convenor, Healthy Rivers Dubbo, 0431 471 310


Professor Richard Kingsford to speak in Dubbo

The proposed Gin Gin dam plans were slammed last year by the NSW Government as they “do not currently demonstrate value for money and an efficient, effective and prudent use of public funds.”

The proposal does not stack up economically, socially or ecologically.

Come along to the Pastoral Hotel on Wednesday 23rd June and hear from:

  • Professor Richard Kingsford, Wetland Ecologist
  • Tony Lees, Trangie Aboriginal Land Council
  • Beverley Smiles, President of Inland Rivers Network
  • and Garry Hall, Private Ramsar Wetland Manager

Wednesday 23rd June, 6.30pm at the Pastoral Hotel, Talbragar Street Dubbo.

Facebook Event

Media Release

Gin Gin re-regulating dam plans slammed by NSW Government.

Last year in an assessment of the project plans for the Gin Gin dam (Macquarie River re-regulating storage project) the Deputy Secretary of DPIE Water Jim Bentley said the project plans had significant deficiencies, and did not meet the requirements to demonstrate value for money and prudent use of public funds.

The Snowy Hydro Legacy Fund project proposal spelt out the reason for the dam –

The largest agricultural use of water in the valley is for irrigated cotton production downstream of Dubbo. This industry is underpinned by water and many of these users hold general security water licences. The investigation of a re-regulating weir will help determine whether the infrastructure will improve the reliability of water for these users in the context of a more variable future climate.

The State significant infrastructure development application for the proposal MUST be cancelled, as the proposal is only for the benefit of the cotton industry.

The expected capital cost of the proposal was also divulged in a release of documents through the NSW Parliament – a massive $84 million before the inevitable cost blow outs.

That is an enormous amount of money to be spent subsidising a privileged industry that is about to be gifted hundreds of millions of dollars of brand new compensable mortgagable property rights as floodplain harvesting licences.

With over 62,000 megalitres of floodplain water licences about to be gifted, why should the public pay an additional $84 million for a destructive project that would offer irrigated cotton another 14,500 megalitres a year? When is enough enough?

Community calls for the business case to be released in it’s current form continue:

  • Will the impact on irrigation in the unregulated Macquarie River downstream of Marbone weir be assessed?
  • What about the huge knock to the recreational fishing industry?
  • The Macquarie Marshes will be devastated
  • There will be fewer kayakers coming to the valley
  • The best camping spot on the Mid-Macquarie will be destroyed
  • There will be less water in the Warren weir

This proposal was dubbed an ineffective use of public funds in February last year, and funding for the business case was delayed by 8 months because of the plan’s significant deficiencies. Once a dud, always a dud – time to dump the Gin Gin dam plan.

NSW Treasury and the Snowy Hydro Legacy Fund tend to agree. Treasury withheld funding for the business case, and the Snowy Hydro Legacy fund flatly refused a request to fund the Environmental Impact Statement.

Documents seen by HRD state that the estimated $84 million capital expense will not be coming from the Snowy Hydro Legacy Fund, as earlier anticipated. No-one wants to pay for this enormous dud.

Read our supplementary submission to the Upper House Inquiry into the rationale for, and impacts of, new dams and other water infrastructure in NSW here.

In September 2019 HRD made a submission to the NSW Upper House Inquiry into the rationale for, and impacts of, new dams and other water infrastructure in NSW.

Our original submission went into detail about:

  • Macquarie River re-regulating storage project
  • Raising of Wyangala dam wall
  • Mole River dam
  • Dungowan Creek dam
  • Western Weirs project

Floodplain Harvesting Rules for the Macquarie-Wambool

Sunday 18 April 2021


Floodplain harvesting licence rules in the water sharing plans for the Macquarie Valley


Healthy Rivers Dubbo (HRD) is a grass roots community network dedicated to providing a strong voice for our local rivers, aquifers and wetlands in the Murray-Darling Basin for the benefit of wildlife, plants and people. We pay our respects to Elders past and present, and acknowledge that this land was never ceded.

HRD are pleased to have the opportunity to comment on the establishment of rules in the water sharing plan (WSP) for floodplain harvesting (FPH) in the Macquarie-Wambool Valley. HRD accepts that FPH in NSW must be licenced.

Before we detail our comments on the proposed rules, there are some critical issues with FPH in general that, as environmental stakeholders and First Nations allies, HRD is obliged to comment on.

Plan Limit and Cap

There is not enough evidence for the public to accept DPIE Water’s claim that total extractions in the Macquarie-Wambool are below the cap and the sustainable diversion limit (SDL).

In recent years, and coinciding with the latest round of FPH policy implementation, environmental stakeholder have started hearing water departments and agencies claiming that Cap limits and SDLs are definitions, not volumes as they were previously understood by the community as being.

We now are witnessing the volumes of FPH being added to the Cap limits, when previously FPH diversions have been considered as going to the environment.

Decisions made about reducing the volume of water to be recovered from irrigation for the environment in the Northern Basin in 2017 were made assuming the large volumes of water that have been taken by FPH were going to the environment.

The Macquarie-Wambool is an over allocated Valley. When Burrendong dam was completed in 1966/67 the yield of the Macquarie River was assessed as 406,000 ML. Too many licences have been issued, and now the total allocation of regulated and supplementary flow water for the system is around 899,000 ML[1].

There is simply too much demand on the Valley for the volume of licences, which is why reliability is around 30% on average and dropping. This low reliability goes a long way towards explaining why irrigators can’t access as much water as their entitlement.

HRD points to a recent report by consultants Slattery and Johnson that shows on farm capacity has increased by a factor of 2.4 times since 1994. This finding fits with our observations and local knowledge. We can see the increased levees as we drive west from Narromine. We know people who were flat out working during the 2017-2020 drought deepening on farm storages and increasing levees saying the land owner wants to hold 2 years water on farm when the drought breaks.

If on farm capacity has increased by 2.4 times since 1994:

  • those earthworks weren’t done for nothing
  • there’s been no increase in licences since then
  • the capacity must be mostly for storing water from FPH diversion, or from water theft

This increase of on farm storage has helped the industry leave a lot of water in their general security and supplementary accounts, as they preference filling up on free, unmeasured water from the floodplain. Not having to access the general security and supplementary accounts is a major reason why irrigators don’t access their full allocation – they don’t need to.

There is no evidence to substantiate the new Cap limit in the Macquarie, and no access to the accredited Cap model reports.

ICAC found that DPIE Water has a practice of favouring irrigation in “a misguided effort to redress a perceived imbalance caused by the Basin Plan’s prioritisation of the environment’s needs[2].

HRD considers that DPIE Water continues to treat First Nations rights to water and the environment like opponents to their endeavours by working out ways to increase Cap limits to suit extraction.

Environmental Outcomes

Macquarie Marshes:

NSW has a legal and moral responsibility to protect the integrity of the internationally significant Macquarie Marshes under the Ramsar Convention, Migratory Bird agreements, the Water Management Act 2000, the Water Act 2007 and the Murray Darling Basin Plan.

“The unregulated floods, particularly the significant large floods, are critical for sustaining this ecosystem of national and international importance[3]

The Macquarie Marshes have reduced in size considerably since growth in FPH diversions.

The Australian Government notified the Ramsar Secretariat in 2010 of a “likely change in ecological character of the Macquarie Marshes Ramsar site”, stating a range of reasons based on scientific evidence, including changes in the flow regime; change in the extent and condition of the wetland vegetation communities in the southern part of the Macquarie Marshes Nature Reserve; change in extent and condition of wetland vegetation communities in the northern section of the Macquarie Marshes Nature Reserve; changes in the ecological character of the Wilgara wetland and; changes in colonial waterbird breeding. [4]


The Macquarie-Wambool River has provided 21% of flows to the Barwon Darling-Baaka Rivers over the long term. Unique in the Northern Basin, The Macquarie-Wambool, Castlereagh and Bogan Rivers are winter and spring fed systems, and provide flows to the Barwon Darling-Baaka when other monsoon fed systems don’t.

Records show that the Macquarie-Wambool connected to the Barwon (at a depth in the Lower Macquarie of at least 50cm) 9 years in 11 before Burrendong dam was built. Development of the valley means connection occurs 5 years in 11 now (as of 2017). Connections between major rivers represent important links for the movement of fish, transfer of energy, riverine biodiversity and providing a diverse aquatic habitat. [5]

HRD considers that DPIE is acting against its own laws by not applying the priority of use and cultural requirements in the Water Management Act 2000 to the application of FPH licencing and rules in the Macquarie-Wambool Valley by reducing allowable FPH diversions to secure environmental improvement for the Ramsar Macquarie Marshes, and increased connectivity with the Barwon Darling-Baaka Rivers.


HRD strongly believes that the modelling used to determine FPH shares in the Macquarie-Wambool is not fit for purpose.

FPH licenced volume determinations will have a permanent detrimental impact on the environment, First Nations rights to water and basic landholder rights. The volume will also determine how large the wealth shift from the public purse to private and corporate hands will be when mortgageable, tradable, compensable licences are issued.

Climate change has not been factored in into the modelling, despite new robust climate/hydrologic datasets developed by DPIE last year for inclusion in the Regional Water Strategies (RWS). With these new datasets, DPIE has been able to come up with a ‘base case’ river system model.

The RWS states: “just relying on our historical data to make water management decisions no longer represents the best course of action and that we have an opportunity to put plans in place to make sure we are prepared and resilient if there are future changes in the climate.”

Against its own advice, DPIE Water have omitted climate change from FPH models. HRD will discuss the impact of neglecting climate change on FPH rule applications under “Discussion of Proposed Rules 1. Account Management”further down in the submission.

There is only a summary Review of NSW Macquarie River Valley Model Build, Scenarios and Environmental Outcomes report publicly available. The independent peer reviewers Alluvium only had access to reports, not the models themselves.

The Model Build Report identifies a lot of highly significant inaccuracies around the meters used to measure river diversions. There’s a lack of real data on floodplain harvesting volumes, despite the FPH policy being in some form of development since 2008. In the Macquarie there’s a +51% error rate/bias upstream of Narromine, which is extremely significant.[6]

In the Macquarie Cudgegong there is 10,254 ML of water being considered for tailwater/rainfall runoff exemption. HRD does not trust the modelling used to come up with that volume. If this significant volume of water is not brought into the FPH licencing framework, it won’t be counted towards the SDL. This form of take would not need to be measured, just ‘monitored’ for assessment under the risk assessment in the Water Resource Plan. Any volume of rainfall runoff harvested above the 10% harvestable right must be licenced.

Return flows aren’t assessed by the models used. Their only function is to attempt to calculate floodwaters captured, not those that return to the river or floodplain environment. There’s a strong chance water that returns to the river or stays on the floodplain is being assessed as FPH diverted volumes.

As stated by Alluvium: “We note the statements in the report that the uncertainty in individual FPH take estimates (leading to entitlements) is still significant and measurement data is needed to improve on that.”[7] This statement confirms that the inaccuracy of the volumes determined as eligible for FPH diversion are significantly incorrect.

For such a critical determination that will seal the fate of many people and much wildlife to be dependent on the use of models that are not up to the job HRD considers to be a negligent act.

Discussion of Proposed Rules

1. Account Management

HRD strongly supports annual accounting for FPH with no “carryover”*

HRD has heard DPIE Water trying to explain that the environment would be better off under 5 year accounting and 500% carryover and we strongly disagree.

DPIE Water is only looking backwards at flood behaviour up to 2009, when they know floods will change their patterns due to climate change.

From the Macquarie Castlereagh RWS, the Valley can expect “reduced frequency of floods, but when they do occur, significantly higher flood flows throughout the entire region, particularly during the summer-autumn period.”

And also from the same RWS:

“just relying on our historical data to make water management decisions no longer represents the best course of action and that we have an opportunity to put plans in place to make sure we are prepared and resilient if there are future changes in the climate.”

HRD considers that under future conditions, 5 year with 500% “carryover”* will lead to greater FPH diversions than 1 year accounting. We find it consistent with ICAC findings (that DPIE Water favours irrigators over First Nations rights to water and the environment) that DPIE Water are trying to tell us that the environment will be better off under 5 year accounting, when they are knowingly not using climate change predictions in their models.

*N.B. HRD rejects DPIE Water’s use of the term “carryover” to describe entitlements for water that does not exist. HRD asks that DPIE Water come up with another term, such as credit accounting.

2. Initial Available Water Determination

HRD strongly supports an initial AWD of 1ML per unit share or less

Alluvium state in their letter reviewing the modelling reports that: “We note the statements in the report that the uncertainty in individual FPH take estimates (leading to entitlements) is still significant and measurement data is needed to improve on that.

DPIE Water know that the volumes licenced are significantly wrong, therefore the precautionary principle must be applied and an initial AWD of no more than 1 ML per unit share be allowed.

FPH diversions have been denying First Nations rights to water and the environment benefit from first flush flows (particularly sharply felt at the end of a drought) for decades. By granting irrigators a generous 500% hot start, DPIE Water are neglecting their legal obligations under the WMA 2000.

3. Permanent Trade

HRD fully supports that permanent trade be restricted to management zones as proposed

While we would prefer FPH access licences not be tradable, we accept that it is a requirement under the Basin Plan that licences are tradable.

It is very important that trade be restricted as proposed:

  • No new works located in management zones A or D as specified in the (as yet un-gazetted) Floodplain Management Plan for the Macquarie Valley Floodplain 2021.
  • No modifications to works located in management zones A or D if the modification would result in an increase in capacity for that work.
  • No new or modified works outside management zones A and D if the construction or modification would result in an increased rate of take for works located in management zone A or D.

4. Granting or amending water supply works nominated by a floodplain harvesting (regulated river) access licence

No new approvals or modifications that increase diversions

HRD would prefer that DPIE Water were very clear that there can be no growth in FPH diversions, as we feel that is not the case through this consultation process.

HRD considers that:

  • no new works approvals should be issued for FPH in the Macquarie Valley
  • no modifications of existing FPH works should be allowed if the capacity of diversions would be increased
  • only maintenance of existing FPH works should be allowed if the maintenance means there would be no increased diversion of water
  • all licences works must allow floodwaters to pass without diversion or significantly slowing the flow for times when diversions are not permitted

5. Access Rules

HRD supports option 2 – prohibiting access until downstream flow targets are met.

There are no clear, measurable protocols that DPIE Water can enact to ensure the priority of use provisions in the WMA 2000 are applied.

HRD recommends end of system flow targets be introduced in the Macquarie Cudgegong regulated WSP. Access rules for FPH in the WSP should specify that FPH diversion may occur only after modelling of a flow event shows that relevant flow targets will be achieved.

Flow targets must aim to achieve:

  • Water sharing priorities under the WMA (ss. 5(3) and 9(1)), which include water for ecosystem health and basic landholder rights (stock and domestic; native title rights);
  • Environmental needs based on NSW Long Term Watering Plans (LTWP) Environmental Water Requirements (EWR);
  • Critical human water needs; and
  • Cultural rights and objectives in addition to Native Title rights.

6. Active Management

HRD supports the use of active management rules to protect 100% of HEW

HRD supports the proposed use of active management rules to protect HEW from FPH diversion when Held Environmental Water (HEW) being used to create an overbank flow in the management zone where active management applies.

However, the rules do not go far enough. HRD considers rules that protect 100% of HEW from diversion even when active management conditions are below 100% must be implemented.

HEW can be present in the system not just from planned releases from storages, but also under supplementary access. It is reasonable to expect supplementary HEW flows would be vulnerable to FPH diversion if the rules aren’t there to protect it.

7. Environmental Flow Rules

Active management rules must be extended to protect 100% of Active EWA

Just as HEW can be used to create overbank flows in the Gum Cowal, Lower Macquarie Upstream and Lower Macquarie Downstream management zones, so too can environmental water allowance sub account 1 (active EWA).

Active EWA and HEW are managed together in the Macquarie Valley, therefore rules that protect HEW must also protect active EWA.

HRD recommends extending the active management application that protects HEW so that active EWA is also protected.

8. Amendment provisions

HRD supports the proposed amendment provisions for the Macquarie Cudgegong regulated WSP.


DPIE Water have consulted with the irrigation industry regularly, and with environmental stakeholders rarely. HRD is concerned that the bias DPIE Water shows irrigation in the management of water in NSW, as reported by ICAC last November, is informing the granting of FPH licences and implementation of WSP rules.

The definition of Cap is being used as an elastic definition that provides the answer that suits the outcome desired.

By not reducing FPH diversions in the Macquarie, DPIE Water has sealed the fate of the declining Wambool River, Macquarie Marshes and Lower Darling-Baaka Rivers and the cultures, wildlife and communities they support.

Yours Sincerely,

Melissa Gray


Healthy Rivers Dubbo

[1] Johnson W J (2005) Adaptive management of a complex social-ecological system: the regulated Macquarie River in south-eastern Australia. Master of Resource Science Thesis, University of New England.

[2] ICAC Investigation into complaints of corruption in the management of water in NSW and systematic non-compliance with the Water Management Act 2000 – November 2020.

[3] (Kingsford and Thomas, 1995; Thomas et al., 2011; Bino et al., 2015b; Thomas et al., 2015


[5] Making the Connection: Designing, delivering and monitoring flows between catchments – making-connection.pdf

[6] Model Build Report Table 3.7

[7] Alluvium Review of NSW Macquarie River Valley Model Build, Scenarios and Environmental Outcomes reports relevant to Floodplain Harvesting Policy implementation