tag:theconversation.com,2011:/us/topics/murray-darling-basin-90412/articlesMurray-Darling Basin – The Conversation2024-02-01T19:03:42Ztag:theconversation.com,2011:article/2195962024-02-01T19:03:42Z2024-02-01T19:03:42ZConsulting firms provided low-quality research on crucial water policies. It shows we have a deeper problem<figure><img src="https://images.theconversation.com/files/572682/original/file-20240201-17-j9u2l0.jpg?ixlib=rb-1.1.0&rect=28%2C17%2C3805%2C2138&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/agriculture-irrigation-silhouette-farmer-tablet-walks-2330622729">maxim ibragimov, Shutterstock</a></span></figcaption></figure><p>Management <a href="https://www.ibisworld.com/au/industry/management-consulting/1896/#IndustryStatisticsAndTrends">consulting revenue</a> in Australia has grown from less than A$33 billion in 2010 to more than $47 billion in 2023. The increasing use of consultants, as well as the <a href="https://theconversation.com/beyond-the-pwc-scandal-theres-a-growing-case-for-a-royal-commission-into-australias-ruthless-corporate-greed-214474">PwC scandal</a>, highlights serious issues with vested interests, integrity and <a href="https://www.theguardian.com/commentisfree/2023/may/18/why-does-australia-rely-on-consulting-firms-such-as-pwc-and-not-on-its-own-public-servants">transparency</a>. </p>
<p>Consequently, a <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Finance_and_Public_Administration/Consultingservices">Senate inquiry</a> is investigating the management and integrity of consulting services. The deadline for the Senate committee’s final report has been extended twice, partly due to the <a href="https://www.themandarin.com.au/236738-the-big-fours-revelations-in-senate-estimates/">various revelations</a>, to March 28. So far, all the big consulting groups in Australia have appeared before the committee. </p>
<p>Our <a href="https://www.sciencedirect.com/science/article/pii/S1462901123003039">recent review</a> of research in the Murray-Darling Basin points to other serious concerns about the use of consulting studies, which are increasingly relied upon for policy-making, especially in water. Of the studies we examined, 65 were on the economic consequences of water recovery. Almost half of these were low-quality studies, mainly from consultancies but also by think tanks and government departments. The low-quality studies were more likely to overestimate negative impacts on the economy and community from buying water back for the environment. </p>
<p>Unfortunately, these poor-quality studies were used to justify changes to water policy. Buying back water rights from “willing sellers” is a <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/1467-8489.12001">cost-effective way</a> to redistribute water entitlements. But buybacks were halted under the former Coalition government. The policy <a href="https://minister.dcceew.gov.au/plibersek/media-releases/getting-straight-work-restore-murray-darling-rivers">will now be restored</a> under Labor in the form of “voluntary water purchases”. </p>
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Read more:
<a href="https://theconversation.com/water-buybacks-are-back-on-the-table-in-the-murray-darling-basin-heres-a-refresher-on-how-they-work-200529">Water buybacks are back on the table in the Murray-Darling Basin. Here's a refresher on how they work</a>
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<h2>Contested research into water buybacks</h2>
<p>The $13 billion basin plan seeks to improve the health of our nation’s largest river system by returning water from irrigation to the environment. </p>
<p>But such water reallocation has been blamed for <a href="https://www.theguardian.com/australia-news/2023/oct/18/murray-darling-basin-water-buyback-plan-farmers-claim-rural-job-losses">huge job losses, reductions in irrigated production and consequently, economic decline in rural towns</a>. </p>
<p>There are many groups with different interests in the basin. Research results are often contested.</p>
<p>To provide an objective assessment and comparison of the quality of basin water economic study results, we developed and applied a <a href="https://www.sciencedirect.com/science/article/pii/S1462901123003039">new economic quality assessment framework</a>. This was inspired by health research, which has long applied grading systems to ensure robustness in research findings (such as <a href="https://www.nhmrc.gov.au/guidelinesforguidelines/develop/assessing-certainty-evidence">the Grading of Recommendations Assessment, Development and Evaluation</a>. </p>
<p>Our framework enables studies to be classified as low, medium or high quality, to suggest how robust each study’s results may be. </p>
<p>Nearly half (45 per cent) of the 65 water recovery studies in our review were classified as low quality. These low quality studies were much more likely to suggest large negative impacts on economic values from water recovery than higher quality studies. They were also more likely to be consulting studies. </p>
<p>The high quality studies (26 per cent) were peer-reviewed, employed sophisticated modelling and extensive analysis. The estimated impact of water recovery ranged from none to small or modest. None of these studies were funded by industry. </p>
<h2>Why is there such a difference in results?</h2>
<p>The method used in each study is a major factor determining research quality. Consultants often rely on simple methods such as “input-output modelling” or “multipliers” to assess economic impact. These are models that often rely upon simplistic assumptions and links within sectors in the economy to predict changes in job numbers or production. These models are not able to consider all possible influences of change. </p>
<p>Input-output modelling is <a href="https://www.abs.gov.au/statistics/detailed-methodology-information/concepts-sources-methods/australian-system-national-accounts-concepts-sources-and-methods/2020-21/chapter-22-input-output-tables/using-i-o-tables-analysis">heavily criticised as inappropriate by the Australian Bureau of Statistics</a> and many treasury departments. Given this modelling is used across many areas and subjects within Australia to illustrate “economic impact”, its use and application needs greater scrutiny. </p>
<p>Higher quality studies use methods that allow for dynamic feedback and adaptation. They also account for other factors that influence outcomes such as climate or prices. As a result, higher quality studies in our review do not find anywhere near the same large decrease in jobs or economic impact from reduced water extraction. </p>
<p>For example, some feedbacks that can occur when farmers sell water include that the money is reinvested on the farm, increasing profits, or that the farm switches from irrigated to dryland agriculture, so production continues. Alternatively water recovery may increase community welfare through an improved environment, or better downstream water conditions for other farmers. Simplistic modelling approaches often ignore these other benefits.</p>
<p>Our <a href="https://www.sciencedirect.com/science/article/pii/S1462901123003039?via%3Dihub">review</a> also indicated a relative lack of study in the basin on other downstream and Indigenous benefits and costs, as well as a need to pay closer attention to transition and adjustment issues within some small irrigation-intensive communities. </p>
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<h2>We need quality standards for water research</h2>
<p>Basin communities will increasingly need to adapt and adjust as the climate changes. We need better ways to cope with such transitions, especially in the face of future upheavals from drought and extreme weather events.</p>
<p>Hopefully the recently released funding and other <a href="https://consult.dcceew.gov.au/draft-restoring-our-rivers-framework">support for communities</a> announced in the amended <a href="https://www.dcceew.gov.au/water/policy/restoring-our-rivers-act">water law</a> will help communities adjust to the reallocation of water. To date, such funds have <a href="https://www.pc.gov.au/inquiries/completed/basin-plan/report">not been allocated</a> to areas most in need.</p>
<p>The negative socio-economic impacts predicted by low-quality studies are often used to justify changed water policies. We, along with other <a href="https://www.pc.gov.au/__data/assets/pdf_file/0007/369142/sub104-basin-plan-2023.pdf">water economic professors</a>, are calling for greater quality standards when it comes to government-funded research into the affects of water reallocation. The government is now <a href="https://storage.googleapis.com/files-au-climate/climate-au/p/prj2a8f4464525d140f6d670/public_assets/Draft450Framework.pdf">required</a> to update the impact analysis for the basin plan. It is essential that any assessment of impact is robust and defensible, following strict quality standards.</p>
<p>These quality standards could also be applied widely, across a variety of policies and areas. Although high quality research is difficult and takes time, relying on inadequate research can have serious consequences. </p>
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Read more:
<a href="https://theconversation.com/suicide-rates-increased-after-extreme-drought-in-the-murray-darling-basin-we-have-to-do-better-as-climate-change-intensifies-211107">Suicide rates increased after extreme drought in the Murray-Darling Basin – we have to do better as climate change intensifies</a>
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<img src="https://counter.theconversation.com/content/219596/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>An Australian Research Council discovery grant and the Murray-Darling Basin Authority provided funding for this research.</span></em></p><p class="fine-print"><em><span>Alec Zuo receives funding from an Australian Research Council discovery grant and the Murray-Darling Basin Authority provided funding for this research.</span></em></p>A comprehensive review of research into the economic consequences of controversial water buybacks in the Murray-Darling Basin reveals many studies are of poor quality. Better standards are needed.Sarah Ann Wheeler, Professor in Water Economics, University of AdelaideAlec Zuo, Associate Professor, School of Economics and Public Policy, University of AdelaideYing Xu, Research Fellow, School of Economics and Public Policy, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2170022023-11-27T04:12:56Z2023-11-27T04:12:56ZThe government’s Murray-Darling bill is a step forward, but still not enough<figure><img src="https://images.theconversation.com/files/561714/original/file-20231126-21-rluebs.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C3058%2C2032&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sunrise-on-murray-river-near-kingstononmurray-1207917046">Philip Schubert, Shutterstock</a></span></figcaption></figure><p>This week, the Senate is debating changes to Australia’s most important water laws. These changes seek to rescue the ailing A$13 billion Murray-Darling Basin Plan to improve the health of our nation’s largest river system. </p>
<p>The <a href="https://www.aph.gov.au/Parliamentary_Business/Bills_Legislation/Bills_Search_Results/Result?bId=r7076">Water Amendment (Restoring Our Rivers) Bill 2023</a> is a crucial step forward. It proposes to lift the Coalition-era cap on water buybacks, allowing the federal government to recover more water for the environment through the voluntary purchase of water entitlements from irrigators.</p>
<p>It also proposes to extend the deadlines for the many beleaguered water-offsetting projects put forward by state governments.</p>
<p>Through the Wentworth Group of Concerned Scientists – an independent group working to secure the long-term health of Australia’s land, water and biodiversity – we strive to restore river health for the basin’s communities, industries and ecosystems. Here we ask whether the bill can fulfil the Albanese government’s <a href="https://anthonyalbanese.com.au/media-centre/labors-plan-to-future-proof-australias-water-resources-butler">2022 election promise</a> to deliver the plan.</p>
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<h2>Securing support of the Greens and crossbenchers</h2>
<p>The bill is central to Prime Minister Anthony Albanese’s <a href="https://anthonyalbanese.com.au/media-centre/labors-plan-to-future-proof-australias-water-resources-butler">five-point election promise</a> to deliver the plan, and Federal Water Minister Tanya Plibersek’s <a href="https://www.tanyaplibersek.com/media/media-releases/media-release-plibersek-decade-of-liberal-national-sabotage-puts-murray-darling-basin-plan-behind/">subsequent commitment</a> to implement the Murray-Darling Basin Plan in full.</p>
<p>With the Coalition <a href="https://www.aph.gov.au/Parliamentary_Business/Bills_Legislation/Bills_Search_Results/Result?bId=r7076">voting against the bill</a> in the lower house, the federal government <a href="https://minister.dcceew.gov.au/plibersek/media-releases/joint-media-release-strengthening-restoring-our-rivers-bill">secured the support</a> of the Greens with measures that considerably strengthen the bill.</p>
<p>It is now up to key crossbench Senators to secure passage through parliament. But they have said the bill doesn’t go far enough, citing serious concerns it <a href="https://www.lidiathorpe.com/mr_water_legislation">excludes First Nations water rights and interests</a> and <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Environment_and_Communications/MDBAWaterBill2023/Report">ignores climate change</a>.</p>
<p>The federal government must pass the bill in the next two sitting weeks to avoid triggering a statutory deadline, after which unfinished water offset projects would be cancelled and water recovery would be required instead.</p>
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Read more:
<a href="https://theconversation.com/labors-new-murray-darling-basin-plan-deal-entrenches-water-injustice-for-first-nations-212261">Labor’s new Murray-Darling Basin Plan deal entrenches water injustice for First Nations</a>
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<h2>Water Act and Basin Plan: where are we at?</h2>
<p>Born of the crisis of the Millennium drought, the Water Act 2007 was announced by the Howard government to “<a href="https://www.theaustralian.com.au/news/howards-full-speech-to-the-national-press-club/news-story/cfd6aa4761027929545602a96dc04254">once and for all</a>” address over-allocation of water in the Murray-Darling Basin.</p>
<p>Five years later, the Basin Plan 2012 was established to recover 3,200 billion litres of water for the environment from other uses, or to implement projects that deliver “equivalent” outcomes. That includes securing 450 billion litres for the health of the River Murray, Coorong and Lower Lakes.</p>
<p>But this volume of water fell substantially short of the Murray-Darling Basin Authority’s best estimate of what was needed to “<a href="http://www6.austlii.edu.au/cgi-bin/viewdoc/au/legis/cth/consol_act/wa200783/s3.html">ensure the return to environmentally sustainable levels of extraction</a>”, and did not take climate change into account.</p>
<p>All water recovery targets were expected to be met by June 2024. But while some progress has been made, water recovery has <a href="https://wentworthgroup.org/2017/11/review-of-water-reform-in-the-murray-darling-basin/">almost stalled</a> in the past decade.</p>
<p>Only <a href="https://www.dcceew.gov.au/water/policy/mdb/progress-recovery">26 billion litres have been recovered</a> of the crucial 450 billion litres. </p>
<p>Of the 36 water offset projects meant to be operational by 2024, <a href="https://www.mdba.gov.au/sites/default/files/publications/2023-sdlam-annual-assurance-report.pdf">16 are not likely to be complete</a>, contributing to a likely shortfall of between 190 billion and 315 billion litres.</p>
<p>No onground work has commenced to alleviate flow “constraints”, leaving thousands of hectares of floodplain forests in the River Murray disconnected from their channels and at risk of drying out and dying.</p>
<p>The Water Act and the plan <a href="https://www.abc.net.au/news/2023-11-14/lawyers-academics-first-nations-rights-murray-darling-basin-plan/103098066">do not provide for First Nations people’s water rights and interests</a>. And they <a href="https://openresearch-repository.anu.edu.au/bitstream/1885/67496/2/01_Pittock_The_Murray-Darling_Basin_Plan_2015.pdf">fail to deal with climate change</a>.</p>
<p>Reforms to both the legislation and the plan are desperately needed to address these major shortcomings.</p>
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Read more:
<a href="https://theconversation.com/murray-darling-basin-plan-to-be-extended-under-a-new-agreement-without-victoria-but-an-uphill-battle-lies-ahead-212002">Murray-Darling Basin Plan to be extended under a new agreement, without Victoria – but an uphill battle lies ahead</a>
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<h2>Voluntary buybacks are necessary</h2>
<p>The new bill represents a clear step towards the first of the Albanese government’s <a href="https://anthonyalbanese.com.au/media-centre/labors-plan-to-future-proof-australias-water-resources-butler">five-point promises</a> to “deliver on water commitments” by removing the cap on buybacks.</p>
<p>Without buybacks, it is unlikely the federal government will be able to deliver the 3,200 billion-litre plan in full.</p>
<p>While the <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Environment_and_Communications/MDBAWaterBill2023/Report">Senate Committee</a> acknowledged the impacts of buybacks on communities, the committee found some concerns were “overinflated and not supported by the high-quality evidence base”, referring to a <a href="https://www.mdba.gov.au/sites/default/files/publications/mdb-outlook-economic-literature-review2.pdf">literature review</a>.</p>
<p>The Wentworth Group has <a href="https://wentworthgroup.org/2010/06/sustainable-diversions-in-the-murray-darling-basin/">long argued</a> for funding to establish a regional transition fund to support impacted communities through these reforms. As part of these reforms, “significant transitional assistance” was <a href="https://minister.dcceew.gov.au/plibersek/speeches/speech-introducing-restoring-our-rivers-bill">announced</a> by Plibersek.</p>
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Read more:
<a href="https://theconversation.com/water-buybacks-are-back-on-the-table-in-the-murray-darling-basin-heres-a-refresher-on-how-they-work-200529">Water buybacks are back on the table in the Murray-Darling Basin. Here's a refresher on how they work</a>
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<h2>Statutory guarantees are needed</h2>
<p>The bill requires <a href="https://wentworthgroup.org/2023/10/submission-to-senate_inquiry_water_amendment_bill_2023/">additional measures</a> to guarantee the unfinished business to which parliament agreed more than a decade ago:</p>
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<li><p><strong>a legally binding 450 billion litre water recovery target</strong>. The public needs a legal recourse if governments fail to deliver the full volume. We understand the intent of today’s <a href="https://minister.dcceew.gov.au/plibersek/media-releases/joint-media-release-strengthening-restoring-our-rivers-bill">announcement</a> is to make the target a statutory requirement, in line with other water recovery targets under the plan.</p></li>
<li><p><strong>improved integrity of the water offset method and withdrawal of unviable water offset projects</strong> The <a href="https://minister.dcceew.gov.au/plibersek/media-releases/joint-media-release-strengthening-restoring-our-rivers-bill">agreement</a> reached today allows the Commonwealth to remove non-viable projects. <a href="https://www.publish.csiro.au/mf/Fulltext/MF22082">Significant flaws</a> in the method used to calculate water offsets still need to be addressed. </p></li>
<li><p><strong>milestones in the bill’s proposed “constraints roadmap”</strong> which specify targets linked to incentive payments.</p></li>
<li><p><strong>transparency and accountability measures</strong> to restore public confidence in water reform, such as whole-of-basin hydrological modelling, water accounting and auditing, and validation of annual permitted take models. </p></li>
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<p>Several of these measures were <a href="https://minister.dcceew.gov.au/plibersek/media-releases/joint-media-release-strengthening-restoring-our-rivers-bill">announced today</a>. We’re yet to see details but the high-level agreement is encouraging.</p>
<h2>Urgent reforms can’t wait to 2027</h2>
<p>Australia’s water laws have <a href="https://theconversation.com/labors-new-murray-darling-basin-plan-deal-entrenches-water-injustice-for-first-nations-212261">failed to address</a> the rights and interests of Indigenous people. Indigenous peoples <a href="https://www.sciencedirect.com/science/article/pii/S0264837719319799">own a mere 0.2%</a> of surface water entitlements in the Murray-Darling Basin.</p>
<p>In 2022, the Albanese government <a href="https://anthonyalbanese.com.au/media-centre/labors-plan-to-future-proof-australias-water-resources-butler">committed</a> to “increasing First Nations ownership of water entitlements and participation in decision making”.</p>
<p>The <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Environment_and_Communications/MDBAWaterBill2023/Report">Senate Committee</a> found “overwhelming support […] that significantly more needs to be done to incorporate the values and interests of First Nations people in Basin Plan management”.</p>
<p>Many solutions can be readily incorporated into the bill. It should be amended so the legislation is consistent with the United Nations Declaration on the Rights of Indigenous Peoples, and recommendations of Indigenous organisations, such as the Murray-Lower Darling Rivers Indigenous Nations.</p>
<p>The $100 million <a href="https://minister.dcceew.gov.au/plibersek/media-releases/joint-media-release-strengthening-restoring-our-rivers-bill">announced</a> today for the Aboriginal Water Entitlement Program is welcome, although much was already <a href="https://www.tonyburke.com.au/media-releases/2019/5/6/media-release-labornbspwillnbspget-the-basin-plan-back-on-tracknbsp">committed</a> and the remainder won’t make up for the lost value given entitlement prices, according to <a href="https://mldrin.org/wp-content/uploads/2023/08/WEB_20230829-MLDRIN-Slide-Deck-FINAL-STC.pdf">analysis</a> commissioned by the Murray-Lower Darling Rivers Indigenous Nations.</p>
<p>The bill also needs to provide greater clarity for basin communities on how climate change will be incorporated into the Basin Plan review, and strategies for adapting to climate change. This cannot wait until 2027 – communities need to prepare now for their future.</p>
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Read more:
<a href="https://theconversation.com/victorias-plans-for-engineered-wetlands-on-the-murray-are-environmentally-dubious-heres-a-better-option-204116">Victoria’s plans for engineered wetlands on the Murray are environmentally dubious. Here’s a better option</a>
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<img src="https://counter.theconversation.com/content/217002/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Celine Steinfeld is Director of the Wentworth Group of Concerned Scientists.</span></em></p><p class="fine-print"><em><span>Michael Vanderzee is a Water Policy Analyst with the Wentworth Group of Concerned Scientists. He is a former water policy adviser to the Victorian goverment with more than 12 years experience in national and Murray-Darling Basin water reform.</span></em></p>With the support of the Greens, there’s a chance the ‘Restoring Our Rivers’ Bill will pass. Will it be enough to put the Murray-Darling Basin Plan back on track?Celine Steinfeld, Director, Wentworth Group of Concerned Scientists & Adjunct Lecturer, UNSW SydneyMichael Vanderzee, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2031422023-11-13T02:49:40Z2023-11-13T02:49:40ZMurray-Darling water buybacks won’t be enough if we can’t get water to where it’s needed<p>When it was clear the Murray-Darling Basin Plan could not be completed on time, Federal Water Minister Tanya Plibersek <a href="https://minister.dcceew.gov.au/plibersek/media-releases/historic-deal-struck-guarantee-future-murray-darling-basin">announced a new agreement</a> (without Victoria) to deliver in full the plan’s aim of restoring the health of this vast river system.</p>
<p>The new agreement required changes to the Water Act to allow more water for the environment to be purchased from irrigators (<a href="https://theconversation.com/water-buybacks-are-back-on-the-table-in-the-murray-darling-basin-heres-a-refresher-on-how-they-work-200529">water buybacks</a>). Concerns about these changes prompted a Senate inquiry. </p>
<p>The <a href="https://www.aph.gov.au/Parliamentary_Business/Tabled_Documents/4142">report</a> from that inquiry, released on Friday, <a href="https://www.abc.net.au/news/rural/2023-11-10/murray-darling-senate-inquiry-more-offset-project-scrutiny/103084420">supports buybacks</a> but also makes key recommendations to remove “constraints” to water delivery. These are physical constraints or limits to the movement of water through the river system. Managers can only deliver so much water before it spills out of the river onto private land. </p>
<p>The report goes so far as to ask whether constraints should be removed before more water is recovered. This is a question we have been asking in our research. And our results suggest the answer is yes.</p>
<p>Currently, we cannot physically deliver all of the water recovered from other uses for the environment (known as <a href="https://www.sciencedirect.com/science/article/abs/pii/B9780128039076000012">environmental water</a>) to where it’s needed without flooding private property along the way. And the government is not prepared to do that. </p>
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Read more:
<a href="https://theconversation.com/murray-darling-basin-plan-to-be-extended-under-a-new-agreement-without-victoria-but-an-uphill-battle-lies-ahead-212002">Murray-Darling Basin Plan to be extended under a new agreement, without Victoria – but an uphill battle lies ahead</a>
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<h2>Basin health is improving but challenges remain</h2>
<p>Under the <a href="https://www.mdba.gov.au/water-management/basin-plan">Basin Plan</a>, about 20% of water used for irrigation a decade ago is now used for environmental purposes. This has improved river health, encouraging fish to spawn and plants to grow, and reduced salt levels in the Lower Lakes and Coorong. </p>
<p>These benefits rely on the river’s <a href="https://www.jstor.org/stable/1313099">flow regime</a>, not just the annual volume. Higher flows inundate wetlands, move sediment down the river, and provide natural triggers for various species to breed or migrate. </p>
<p>But raising water levels in the river channel isn’t enough to get environmental water everywhere it’s needed. Sometimes larger flows are required. Unfortunately, sending more water down the river runs the risk of inundating private property or damaging infrastructure such as low-lying pumps on floodplains. </p>
<p>Restoring the river’s health requires not only recovering water but also completing projects that allow more of this water to flow despite physical constraints such as a narrow stretch of river. These <a href="https://www.dcceew.gov.au/water/policy/mdb/policy/sdl-adjustment-mechanism">projects</a> might involve modifying or improving infrastructure such as low-lying roads and bridges, as well as working with communities to limit damage and compensate for flooding of private property.</p>
<p>The Senate inquiry report highlights the challenges for these projects. It also supports improving the approach to delivering these projects across the southern basin. </p>
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<h2>Challenges, priorities and solutions may differ</h2>
<p><a href="https://www.frontiersin.org/articles/10.3389/fenvs.2021.789206/full">Our research</a> on the Goulburn River in Victoria’s part of the Murray-Darling Basin shows recovery of additional water for the environment does not guarantee environmental outcomes. </p>
<p>This is because the amount of water that can be sent down the river is constrained. So having more environmental water at your disposal does not help, because it is physically impossible to get all the water to where it is needed, when it is needed, without risking inundation of private property.</p>
<p>Current river system operations, including rules and physical constraints, prevent the full volume of environmental water held in Goulburn River being delivered at the right time and in the right way to achieve the best environmental outcomes.</p>
<p>Narrow sections of the river and adjacent private development limit releases from Lake Eildon. River managers are not allowed to deliberately inundate the floodplain if it risks private property. </p>
<p>So the volume of environmental water available in the Goulburn River is not the issue – delivering this water is the challenge. In this regard, <a href="https://theconversation.com/murray-darling-basin-plan-to-be-extended-under-a-new-agreement-without-victoria-but-an-uphill-battle-lies-ahead-212002">Victoria’s refusal</a> to sign up to the new basin deal is understandable, because more water buybacks would potentially cause more pain to the local community than gain to the local environment. </p>
<p>However, neither Victoria nor New South Wales has addressed these capacity constraint issues, significantly limiting the ability to get better environmental outcomes with less water. So the challenge is much more complex than simply redistributing entitlements and buying back environmental water. </p>
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<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/water-buybacks-are-back-on-the-table-in-the-murray-darling-basin-heres-a-refresher-on-how-they-work-200529">Water buybacks are back on the table in the Murray-Darling Basin. Here's a refresher on how they work</a>
</strong>
</em>
</p>
<hr>
<h2>The elephant in the room: climate change</h2>
<p>Temperature, rainfall and streamflow have already changed in parts of the Murray-Darling Basin. Over the coming decade these changes will become more pronounced, <a href="https://www.sciencedirect.com/science/article/pii/S002216942300313X">widespread and entrenched</a>, causing more frequent floods and droughts. </p>
<p>While the precise consequences for water availability remain to be seen, the impact on the basin will be immense. </p>
<p>But climate change simply adds to the need to have difficult conversations around the future of communities along the Murray-Darling. Focusing on whether buyback targets have been achieved does not resolve this. In many regions, there will not be enough water, with or without buybacks, to achieve <a href="https://cdn.environment.sa.gov.au/environment/docs/6.8.1-Preliminary-adaptation-pathways-for-the-Coorong-Lower-Lakes-and-Murray-Mouth.pdf">current management objectives</a>. </p>
<p>Buybacks should be placed in the context of this imminent threat. In rivers like the Goulburn, addressing capacity constraints provides the <a href="https://www.frontiersin.org/articles/10.3389/fenvs.2021.789206/full">single best climate adaptation option</a> to improve environmental outcomes in the short and medium term. </p>
<p>Removing these constraints would allow more water onto the lower Goulburn River floodplain, with due care for land and infrastructure that could be affected. For example, projects may offer landholders <a href="https://www.gbcma.vic.gov.au/our-region/waterway-floodplain-management/waterways/constraints-management-strategy">options to avoid or compensate for any water damage and associated costs</a>. </p>
<p>This is because removing constraints gives river managers more flexibility, which can increase the resilience of the environment to a wider range of future climates. More water from buybacks provides very limited additional benefit because it doesn’t change how environmental water can be delivered. </p>
<p>The senate report emphasises the need to embed consideration of climate change in the Water Act and Basin Plan. The decisions we are making now on water recovery and constraints relaxation will have big impacts on communities.</p>
<p>Our work shows considering climate change is essential to ensuring lasting benefits and resilient outcomes for the rivers and communities that rely on them.</p>
<p>The first basin plan took a big step towards sustainable management of the vast Murray-Darling river system. But it was always meant to be the first step in an adaptive policy process. Priorities and solutions will look different across the basin. We need a holistic approach where buybacks may very well be part of the solution, but are not the whole solution. We also need to ensure we can deliver this water where and when the environment needs it. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/victorias-plans-for-engineered-wetlands-on-the-murray-are-environmentally-dubious-heres-a-better-option-204116">Victoria’s plans for engineered wetlands on the Murray are environmentally dubious. Here’s a better option</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/203142/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Avril Horne receives funding from the Victorian Government Department of Energy, Environment and Climate Action.
Avril has recently been appointed as a member of the Murray-Darling Basin Authority Advisory Committee on Social Economic and Environmental Sciences.</span></em></p><p class="fine-print"><em><span>Andrew John receives funding from the Victorian Government Department of Energy, Environment and Climate Action. </span></em></p>Buying back water from irrigators across the Murray-Darling Basin will not be enough to restore river health because we have big problems getting this ‘environmental water’ to where it’s needed most.Avril Horne, Research fellow, Department of Infrastructure Engineering, The University of MelbourneAndrew John, Research fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2111072023-10-05T03:16:20Z2023-10-05T03:16:20ZSuicide rates increased after extreme drought in the Murray-Darling Basin – we have to do better as climate change intensifies<p>The <a href="https://www.nature.com/articles/s41558-018-0102-4">impact on mental health of weather extremes</a> such as drought is a growing concern due to climate change.</p>
<p>Rural communities feel the impact of drought much more than urban residents. Our <a href="https://www.worldscientific.com/doi/full/10.1142/S2010007823500240">new research</a> looks at the link between drought and suicide rates in one of Australia’s biggest farming areas, the Murray-Darling Basin. </p>
<p>Drawing on monthly data from 2006 to 2016, our findings were alarming. We found, for instance, that one more month of extreme drought in the previous 12 months was strongly associated with a 32% increase in monthly suicide rates. </p>
<p>Climate change is <a href="https://www.ipcc.ch/report/ar6/wg1/">predicted</a> to bring more heat and <a href="https://publications.csiro.au/publications/publication/PIcsiro:EP201750">longer, more extreme droughts</a>. More effective approaches will be needed to prevent suicides in affected regions. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1541420049952415744"}"></div></p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/drought-increases-rural-suicide-and-climate-change-will-make-drought-worse-185392">Drought increases rural suicide, and climate change will make drought worse</a>
</strong>
</em>
</p>
<hr>
<h2>Drought hits rural areas hardest</h2>
<p>Droughts induce <a href="https://www.pnas.org/doi/full/10.1073/pnas.1801528115">post-traumatic stress disorder, anxiety and depression</a>. Hotter temperatures can also <a href="https://www.bcm.edu/news/excessive-heat-and-its-impact-on-mental-health#:%7E:text=Heat%20alters%20those%20behaviors%20because,levels%20of%20stress%20and%20fatigue.">reduce levels of the brain chemical serotonin</a>. This has negative effects on the <a href="https://link.springer.com/article/10.1007/s11356-019-05252-5">central nervous system and moods</a>. </p>
<p>In Australia, suicide is a <a href="https://www.abs.gov.au/statistics/health/causes-death/causes-death-australia/latest-release#key-statistics">leading cause of death</a> – especially for people aged 18-44. And the suicide rate in remote areas is <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Community_Affairs/MentalHealthServices/Report">almost double that of major cities</a>. This is because drought can:</p>
<ul>
<li><a href="https://www.jstor.org/stable/24721393">reduce agricultural production</a><br></li>
<li><a href="https://onlinelibrary.wiley.com/doi/full/10.1111/1467-8489.12218">increase financial hardship</a></li>
<li><a href="https://journals.sagepub.com/doi/10.1080/10398560701701288">degrade the environment</a> </li>
<li><a href="https://www.nature.com/articles/s41558-018-0102-4">reduce employment</a>. </li>
</ul>
<p><a href="https://www.nature.com/articles/s41558-018-0222-x">Research overseas</a> found suicide rates rise with higher average temperatures. In Australia, a study found some evidence linking <a href="https://www.pnas.org/doi/full/10.1073/pnas.1112965109">drought and suicide</a> in New South Wales. However, a <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1440-1584.2011.01244.x?saml_referrer">Victorian study</a> found no significant association.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bushfires-drought-covid-why-rural-australians-mental-health-is-taking-a-battering-148724">Bushfires, drought, COVID: why rural Australians' mental health is taking a battering</a>
</strong>
</em>
</p>
<hr>
<h2>What happened in the basin?</h2>
<p><a href="https://www.worldscientific.com/doi/full/10.1142/S2010007823500240">Our study</a> looked at the Murray-Darling Basin. The region went through one of the worst droughts on record, the Millennium Drought, over the past couple of decades. </p>
<p>We analysed local area monthly data from 2006-16. We wanted to see whether worsening drought and heat were linked to higher monthly suicide rates, by examining differing types of droughts (moderate to extreme). </p>
<p>The map below shows the average suicide rate for 2006-2016 in local areas across the basin. Male suicide rates were over three times female rates.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=447&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=447&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=447&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=562&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=562&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541610/original/file-20230808-19-kenxlv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=562&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Average suicide rate per 100,000 by local area in the Murray Darling Basin.</span>
<span class="attribution"><a class="source" href="https://www.worldscientific.com/doi/full/10.1142/S2010007823500240">Source: Xu et al (2023) using data from National Cause of Death Unit Record File from Australian Coordinating Registry (2006-2016) and ABS Population Census, 2006, 2011, 2016</a></span>
</figcaption>
</figure>
<p>We sought to control for as many local area characteristics as possible. Our modelling included unemployment, income, education, proportion of farmers, proportion of Indigenous people, health professionals, green space and various climate and drought variables. We modelled suicide rates for different age and gender sub-groups. </p>
<p>Key findings include:</p>
<ul>
<li>one more month of extreme drought in the previous 12 months was strongly associated with the total suicide rate increasing by 32%</li>
<li>one more month of moderate drought in the previous 12 months was very weakly associated with a 2% increase in the suicide rate</li>
<li>a 1°C increase in average monthly maximum temperature in the previous 12 months was associated with up to an 8% increase in the suicide rate </li>
<li>in males and younger age groups, suicide rates are more strongly associated with extreme drought and higher temperatures</li>
<li>a higher proportion of farmers in a local area was associated with an increased suicide rate </li>
<li>a higher proportion of First Nations people in a local area was also associated with higher suicide rates</li>
<li>more green space was significantly associated with moderating impacts of both extreme drought and temperature on suicide rates</li>
<li>an increase in average annual household income moderated the relationship between higher temperature and suicide.</li>
</ul>
<p>Our results suggest the association between moderate drought and suicide rates is significant but the effect was small. As the drought becomes extreme, suicide rates increase significantly. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-findings-show-a-direct-causal-relationship-between-unemployment-and-suicide-209486">New findings show a direct causal relationship between unemployment and suicide</a>
</strong>
</em>
</p>
<hr>
<h2>What can we do better to prevent suicides?</h2>
<p>Given drought’s impact on farm production and finances, mental health will clearly get worse in rural areas if the impacts of climate change are not better managed. </p>
<p>Mental health interventions to prevent suicide in <a href="https://www.mdpi.com/1660-4601/19/13/7855">rural areas</a> are different from what’s needed in urban areas. Areas in the basin with higher percentages of farmers and First Nations people were hot spots. These areas may need special intervention. </p>
<p>Many have emphasised the need for a <a href="https://www.blackdoginstitute.org.au/wp-content/uploads/2021/05/The-National-Suicide-Prevention-Trials-Insights-and-Impact_Jan-2021-V3.pdf">systems approach to suicide prevention</a>. Actions need to be multifaceted and co-ordinated as well as possible. One intervention or approach is not enough. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/hairdressers-in-rural-australia-end-up-being-counsellors-too-70275">Hairdressers in rural Australia end up being counsellors too</a>
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</em>
</p>
<hr>
<p>Interventions in the bush range from telehealth and medical services to <a href="https://www.health.gov.au/our-work/aboriginal-and-torres-strait-islander-mental-health-program">primary health networks services</a>, <a href="https://mensshed.org/">men’s sheds</a> and drought counselling. </p>
<p>The relationship between <a href="https://www.mja.com.au/journal/2018/209/4/drought-related-stress-among-farmers-findings-australian-rural-mental-health">drought and financial hardship</a> seems to be key in farming areas. This points to the need for other forms of income on the farm, including from native vegetation and carbon credits. Work can also be done to promote drought preparedness, increase appropriate regional economic, social development and environmental policies and – where necessary – help people leave farming. </p>
<hr>
<p><em>If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14.</em></p><img src="https://counter.theconversation.com/content/211107/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Ann Wheeler has received funding from the Australian Research Council; GRDC; Wine Australia; MDBA; CRC Food Waste; CSIRO; Goyder Institute; SA Department of Environment and Water; ACCC; NT Department of Environment, Parks and Water Security; NSW Health; Commonwealth Department of Agriculture and Water; Meat and Livestock Australia; ACIAR; RIRDC; UNECE; NCCARF; National Water Commission; and the Government of Netherlands.</span></em></p><p class="fine-print"><em><span>Alec Zuo receives funding from the Australian Research Council, GRDC, ACCC, NSW Health, Department of Agriculture, Fisheries and Forestry, ACIAR, NCCARF, and the National Water Commission.</span></em></p><p class="fine-print"><em><span>Ying Xu does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Suicide rates jumped in the Murray Darling Basin following extreme drought and hotter temperatures, a new study shows. The findings highlight the need for action to manage climate change impacts.Sarah Ann Wheeler, Professor in Water Economics, University of AdelaideAlec Zuo, Associate Professor, School of Economics and Public Policy, University of AdelaideYing Xu, Research Fellow, School of Economics and Public Policy, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2122612023-08-31T20:00:20Z2023-08-31T20:00:20ZLabor’s new Murray-Darling Basin Plan deal entrenches water injustice for First Nations<figure><img src="https://images.theconversation.com/files/545685/original/file-20230831-15-aututx.jpg?ixlib=rb-1.1.0&rect=55%2C96%2C4561%2C3371&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Erin O’Donnell</span></span></figcaption></figure><p>The federal government has struck a new <a href="https://www.dcceew.gov.au/sites/default/files/documents/agreement-mdbp-delivery-full.pdf">deal</a> with most of the states in the nation’s largest river system. The agreement, announced last week, extends the $13 billion 2012 Murray-Darling Basin Plan to rebalance water allocated to the environment, irrigators and other uses. </p>
<p>Environment and Water Minister Tanya Plibersek said the government has:</p>
<blockquote>
<p>negotiated a way to ensure there is secure and reliable water for communities, agriculture, industry, First Nations and the environment.</p>
</blockquote>
<p>But there is no mention of water for First Nations in the agreement. This follows a history of Indigenous peoples being shortchanged by Murray-Darling Basin planning. Yet again, this latest deal ignores First Nations’ interests, despite millennia of <a href="https://www.smh.com.au/politics/federal/first-nations-call-on-government-to-end-water-rights-drought-20210107-p56sg4.html">custodianship</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/murray-darling-basin-plan-to-be-extended-under-a-new-agreement-without-victoria-but-an-uphill-battle-lies-ahead-212002">Murray-Darling Basin Plan to be extended under a new agreement, without Victoria – but an uphill battle lies ahead</a>
</strong>
</em>
</p>
<hr>
<h2>Shortchanged in reforms</h2>
<p>The <a href="https://www.mdba.gov.au/water-management/basin-plan">Murray-Darling Basin Plan</a> was agreed in 2012 to try and improve the health of the largest and most complex river system in Australia. </p>
<p>It was a historic compromise that sought to address the often conflicting demands of states, irrigators and the environment. But the plan <a href="https://theconversation.com/aboriginal-voices-are-missing-from-the-murray-darling-basin-crisis-110769">overlooked First Nations rights</a> to own, manage and control water on Country. The plan’s current provisions include only <a href="https://research-repository.griffith.edu.au/handle/10072/409545">weak requirements</a> for governments to “have regard to” First Nations values and uses. </p>
<p>In 2018 the Turnbull government put $40 million on the table for First Nations. This deal offered a <a href="https://theconversation.com/deal-on-murray-darling-basin-plan-could-make-history-for-indigenous-water-rights-96264">glimmer of hope</a> as it saw the then water minister David Littleproud and Labor water spokesperson Tony Burke commit the funds to support Basin First Nations’ investment in cultural and economic water entitlements.</p>
<p>But despite Labor renewing the commitment as part of its 2022 election platform, the <a href="https://www.abc.net.au/news/2023-04-29/first-nations-groups-urge-progress-on-water-delivery/102273040">money remains with government and has not been spent</a>. Last week, Plibersek <a href="https://minister.dcceew.gov.au/plibersek/transcripts/press-conference-sydney-minister-environment-and-water-tanya-plibersek-0">said</a> that when Labor came into government there was “very little work done about how this might happen”, and that “it is proceeding”. </p>
<p>A commitment of $40 million is also a paltry amount in the context of the wider river basin. Water research firm Aither’s 2023 <a href="https://aither.com.au/wp-content/uploads/2023/08/2022-23-Water-Markets-Report.pdf">Water Market Report</a> estimates the total value of water entitlements in the southern basin as $32.3 billion, so the government commitment of $40 million is only 0.1% of the total. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Aerial view of Brewarrina historical Aboriginal fish traps on the Barwon River in the far north west of New South Wales." src="https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545687/original/file-20230831-15-5k9rfn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The heritage-listed stone Brewarrina fish traps on the Barwon River, which feeds into the Darling River.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/brewarrina-historical-aboriginal-fish-traps-on-1820794748">John Carnemolla, Shutterstock</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/water-injustice-runs-deep-in-australia-fixing-it-means-handing-control-to-first-nations-155286">Water injustice runs deep in Australia. Fixing it means handing control to First Nations</a>
</strong>
</em>
</p>
<hr>
<h2>Shortchanged in the market</h2>
<p>First Nations organisations have maintained pressure on the federal government and attempted to hold successive ministers to account for <a href="https://www.smh.com.au/politics/federal/betrayal-first-nations-warning-to-government-over-water-fund-pledge-20210505-p57p4u.html">unnecessary delays</a> in delivering the funding. </p>
<p>These delays mean the committed funds are decreasing in value. </p>
<p>When Littleproud initially committed the $40 million, the money was equally split between the northern and southern regions of the basin. Aither <a href="https://mldrin.org/wp-content/uploads/2023/08/WEB_20230829-MLDRIN-Slide-Deck-FINAL-STC.pdf">analysis</a> conducted for the <a href="https://mldrin.org/">Murray Lower Darling Rivers Indigenous Nations</a> shows at today’s prices, the $20 million for Nations in the southern basin can only buy two-thirds of the water that could have been acquired in 2018. In 2023, buying the same volume of water that could have been purchased in 2018 will cost almost $11 million more.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/terra-nullius-has-been-overturned-now-we-must-reverse-aqua-nullius-and-return-water-rights-to-first-nations-people-180037">Terra nullius has been overturned. Now we must reverse aqua nullius and return water rights to First Nations people</a>
</strong>
</em>
</p>
<hr>
<h2>A fair go: investment and reform needed</h2>
<p>Limited government investment from other sources has supported some Basin First Nations to <a href="https://doi.org/10.1080/07900627.2020.1867520">develop</a> <a href="https://www.kaiejin.org.au/pdf/Establishing%20a%20Cultural%20Flows%20Model%20on%20Tati%20Tati%20Country">plans</a> that could guide water use, to nourish their Country, maintain culture, and generate <a href="https://law.unimelb.edu.au/centres/creel/research/current-research-projects/cultural-water-for-cultural-economies">sustainable livelihoods</a>.</p>
<p>However, realising these opportunities means they need water. In an overallocated river system, amid water scarcity and rising prices, this requires genuine political will coupled with necessary reforms and adequate funding.</p>
<p>As another drought looms, and water entitlement prices remain high, more than 40 Basin Nations must share very limited funding that can only acquire a tiny – and diminishing – fraction of their water needs. These deals demonstrate sustained and systemic bipartisan political indifference to First Nations’ inherent rights. </p>
<p>If Plibersek is sincere about delivering “secure and reliable water” for First Nations, she must listen to First Nations people, and actually deliver tangible outcomes. Governments must urgently commit adequate funding for First Nations in the basin to secure water that meets our needs, before future generations are priced out of the market forever. </p>
<p>Funding for cultural flows must be coupled with reform to <a href="https://www.science.org/doi/10.1126/science.adi0658">transform</a> the <a href="https://theconversation.com/water-injustice-runs-deep-in-australia-fixing-it-means-handing-control-to-first-nations-155286">foundations</a> of water governance and implement the <a href="https://mldrin.org/what-we-do/cultural-flows/">Echuca Declaration</a>. This declaration establishes cultural flows as the “inherent rights” of all First Nations in the Basin. </p>
<p>As a start, the Water Act 2007 needs to be strengthened to enshrine Basin Nations’ authority and ensure their voices are heard. </p>
<p>As the terms of the basin plan <a href="https://www.pc.gov.au/inquiries/current/basin-plan-2023#draft">implementation</a> are being reassessed and renegotiated, governments have an opportunity not only to listen, but also to deal First Nations in.</p><img src="https://counter.theconversation.com/content/212261/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Grant Rigney is a citizen of the Ngarrindjeri Nation and Chair of the Murray Lower Darling Rivers Indigenous Nations (MLDRIN). He is also a member of the Committee on Aboriginal Water Interests and Chair of the Ngarrindjeri Regional Authority. Grant is a member of the Greens Party. MLDRIN receives funding from the Australian, Victorian and NSW governments.</span></em></p><p class="fine-print"><em><span>Dr Erin O'Donnell is a settler who lives and works on unceded Wurundjeri Woi-wurrung Country. She is a member of the Birrarung Council, appointed by the Victorian Minister for Water. She receives funding from the Australian Research Council (DE230100622). She has received funding in the past from the state government of Victoria, the Murray Lower Darling Rivers (MLDRIN), the Federation of Victorian Traditional Owner Corporations, the Coalition of Aboriginal and Torres Strait Islander Peak Organizations.
</span></em></p><p class="fine-print"><em><span>Fred Hooper is a Murrawarri man from the Murrawarri Nation. Fred is the Chair of the Murrawarri Peoples Council and former Chair of the Northern Basin Aboriginal Nations (NBAN). He is also a member of the Blak Sovereign Movement. NBAN has previously received funding from the federal and state governments. </span></em></p><p class="fine-print"><em><span>Dr Lana D. Hartwig is a settler who lives and works on unceded Yugambeh Country. She is employed by Murray Lower Darling Rivers Indigenous Nations (MLDRIN). She has received funding in the past from the Murray-Darling Basin Authority and the Coalition of Aboriginal and Torres Strait Islander Peak Organizations.
</span></em></p>Once again, First Nations in the Murray-Darling Basin have been shortchanged in water reform and shortchanged in the water market. It’s time to listen and actually deliver tangible outcomes.Grant Rigney, Indigenous KnowledgeErin O'Donnell, Senior Lecturer, Melbourne Law School, The University of MelbourneFred Hooper, Indigenous knowledge holder, Indigenous KnowledgeLana D. Hartwig, Adjunct Research Fellow, Australian Rivers Institute, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2055712023-07-02T20:02:18Z2023-07-02T20:02:18ZThe Murray-Darling Basin shows why the ‘social cost of water’ concept won’t work<figure><img src="https://images.theconversation.com/files/533850/original/file-20230625-98671-sa646o.jpeg?ixlib=rb-1.1.0&rect=31%2C3%2C2066%2C1394&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source"> Kate McBride</span></span></figcaption></figure><p>Access to safe, clean water is a basic <a href="https://www.unwater.org/water-facts/human-rights-water-and-sanitation">human right</a>. But water scarcity or barriers to access can cause conflict within and between countries. </p>
<p>Fights over water can be expected to <a href="https://www.un.org/en/climatechange/science/climate-issues/water">intensify as the world warms</a>, evaporation increases and rainfall becomes less predictable. So we’ll need to work even harder to resolve disputes and share this precious resource. </p>
<p>Earlier this year, for the first time in almost half a century, the <a href="https://www.unwater.org/news/un-2023-water-conference">United Nations held a conference squarely focused on water</a>. Thousands of water experts gathered in New York for three days in March, to chart a way forward. </p>
<p>We were among the delegates. Since then, we have discussed and debated ideas that surfaced at this international meeting. Some were worthwhile, but others were wrong. In particular, we challenge the concept of a global “social cost of water”. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Infographic outlining the UN 2023 Water Conference vision statement" src="https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/532807/original/file-20230620-46525-4a5amn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Picturing The UN 2023 Water Conference vision.</span>
<span class="attribution"><a class="source" href="https://www.unwater.org/news/un-2023-water-conference">UN 2023 Water Conference</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/were-ignoring-the-value-of-water-and-that-means-were-devaluing-it-207936">We're ignoring the value of water – and that means we're devaluing it</a>
</strong>
</em>
</p>
<hr>
<h2>What is a global social cost of water?</h2>
<p>One of the big ideas that came up at the conference was the need for a “new economics of water as a common good”, which includes the “social cost of water”. </p>
<p>Elaborating on his idea <a href="https://www.nature.com/articles/d41586-023-00800-z">in the journal Nature</a>, Swedish scientist Johan Rockström and colleagues wrote:</p>
<blockquote>
<p>[Researchers] must assess the ‘social cost of water’, akin to the ‘social cost of carbon’, which considers the costs to society of loss and damage caused by water extremes and not meeting the basic provision of water for human needs.</p>
</blockquote>
<p>The <a href="https://www.rff.org/publications/explainers/social-cost-carbon-101/">social cost of carbon</a> is an estimate, in dollars, of the economic damages that would result from emitting one additional tonne of carbon dioxide into the atmosphere. It’s a decision-making tool used by governments, especially in the United States, for cost-benefit analysis of climate policy. </p>
<p>The social cost of water concept proposes valuing all types of water, including water vapour in the atmosphere that later falls as rain. This means attempting to put a dollar value on moisture flowing across borders, and implicitly creating world water markets. According to this logic, if <a href="https://www.nature.com/articles/d41586-023-00800-z">most of Nigeria’s rain</a> comes from forests in central Africa, then Nigeria should be prepared to pay central African nations to maintain the source of this moisture generation. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1638209350463541248"}"></div></p>
<p>But we believe the concept of a global social cost of water is fundamentally flawed, as we explained in our <a href="https://www.nature.com/articles/d41586-023-01564-2/">correspondence in Nature</a> in May, alongside <a href="https://www.nature.com/articles/d41586-023-01563-3">others</a> who also questioned its logic and purpose. Further correspondence in June also described calls to govern water on a global scale as “<a href="https://www.nature.com/articles/d41586-023-01924-y">unrealistic</a>” and distracting from sustainable and equitable access. </p>
<p>It’s unclear how a global social cost of water would work in practice. Writing as economists who have studied local water markets for decades, we see many problems with the concept, such as: </p>
<ul>
<li><p>how water moisture volumes would be estimated reliably and regularly</p></li>
<li><p>how a dollar value could be reliably associated with water moisture flows across borders</p></li>
<li><p>how payments would be enforced between countries, and by what institutions</p></li>
<li><p>whether the money paid between countries would actually improve water security</p></li>
<li><p>what would happen when moisture flows across borders lead to floods with loss of human lives – would the downwind country receive compensation for water disasters as well as droughts? </p></li>
</ul>
<p>Australia has the most sophisticated water markets in the world, in the Murray-Darling Basin. But even here there are <a href="https://academic.oup.com/oxrep/article-abstract/36/1/132/5696682">considerable differences in how markets work</a>. Water values and costs are also very different.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-the-social-cost-of-carbon-2-energy-experts-explain-176255">What is the ‘social cost of carbon’? 2 energy experts explain</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="A man looks out of the second-storey window of his flooded shack at Scott’s Creek, Morgan." src="https://images.theconversation.com/files/534965/original/file-20230630-23-ziw4ih.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534965/original/file-20230630-23-ziw4ih.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534965/original/file-20230630-23-ziw4ih.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534965/original/file-20230630-23-ziw4ih.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534965/original/file-20230630-23-ziw4ih.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534965/original/file-20230630-23-ziw4ih.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534965/original/file-20230630-23-ziw4ih.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In December, 2022, the swollen Murray River flooded homes in South Australia. The floodwater reached the second floor of Darren Davey’s shack at Scott’s Creek, Morgan.</span>
<span class="attribution"><a class="source" href="https://photos.aap.com.au/search/murray%20flood?q=%7B%22pageSize%22:25,%22pageNumber%22:2%7D">MATT TURNER, AAP</a></span>
</figcaption>
</figure>
<h2>Australia’s Murray-Darling Basin: a case in point</h2>
<p>The value of water in the Basin consists of benefits and costs. Some benefits include:</p>
<ul>
<li><p>direct use of water to grow crops or irrigate pasture</p></li>
<li><p>recreational use such as boating and water sports</p></li>
<li><p>indirect use including the benefits to health and wellbeing from living alongside a natural water body</p></li>
<li><p>future use values, knowing there is sufficient water to sustain healthy ecosystems and rivers in years to come</p></li>
<li><p>future generational, existence and cultural values such as non-use values associated with the ancient <a href="https://www.theguardian.com/australia-news/2015/jul/10/fish-traps-brewarrina-extraordinary-ancient-structures-protection">Brewarrina fish traps</a>. </p></li>
</ul>
<p>Costs include harm to mental health associated with a lack of water during drought. At the other extreme, there’s the cost of too much water causing floods, property damage and loss of life, or salinity harming viticulture in the Riverland. </p>
<p>This shows the social value of water is incredibly difficult to measure even within one area such as the Basin, let alone trying to enforce a global water market.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/water-buybacks-are-back-on-the-table-in-the-murray-darling-basin-heres-a-refresher-on-how-they-work-200529">Water buybacks are back on the table in the Murray-Darling Basin. Here's a refresher on how they work</a>
</strong>
</em>
</p>
<hr>
<h2>What should instead happen next?</h2>
<p><a href="https://www.nature.com/articles/d41586-023-01564-2">We think the best way</a> to address the water crisis is to focus on local management and institutions, plan carefully and implement a wide range of policies. These include: </p>
<ul>
<li><p>using economic methods and tools to assess and implement local water policies where feasible</p></li>
<li><p>removing subsidies that incentivise water exploitation</p></li>
<li><p>establishing sustainable extraction limits</p></li>
<li><p>strengthening water institutions to allow measurement, monitoring and enforcement of water use</p></li>
<li><p><a href="https://reliefweb.int/report/world/what-why-and-how-world-water-crisis-global-commission-economics-water-phase-1-review-and-findings">promoting water justice and sharing</a>. </p></li>
</ul>
<p>This is a big task. Misdirection down blind alleys is a distraction that the world cannot afford.</p>
<iframe style="border-radius:12px" src="https://open.spotify.com/embed/episode/42TLwJwAxQ8uE0bYuZNufh?utm_source=generator" width="100%" height="152" frameborder="0" allowfullscreen="" allow="autoplay; clipboard-write; encrypted-media; fullscreen; picture-in-picture" loading="lazy"></iframe><img src="https://counter.theconversation.com/content/205571/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Ann Wheeler has received funding from the Australian Research Council; GRDC; Wine Australia; MDBA; CRC Food Waste; CSIRO; Goyder Institute; SA Department of Environment and Water; ACCC; NT Department of Environment, Parks and Water Security; NSW Health; Commonwealth Department of Agriculture and Water; Meat and Livestock Australia; ACIAR; RIRDC; UNECE; NCCARF; National Water Commission; and the Government of Netherlands.</span></em></p><p class="fine-print"><em><span>The International Food Policy Research Institute, where Claudia Ringler works, receives funding from a considerable number of donors; none of which is linked to this piece. Claudia Ringler is a member of the International Advisory Committee (IAC) of UNU-INWEH.</span></em></p>After almost half a century, the United Nations has waded back into the murky world of water policy. But one of the ideas following this year’s international meeting has been shot down.Sarah Ann Wheeler, Professor in Water Economics, University of AdelaideClaudia Ringler, Deputy Director, Environment and Production Technology Division, International Food Policy Research Institute (IFPRI) Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2071552023-06-26T04:56:38Z2023-06-26T04:56:38ZSoil erosion is filling vital inland river waterholes, putting the squeeze on fish, turtles and crayfish<figure><img src="https://images.theconversation.com/files/531528/original/file-20230613-26-wznt2l.JPG?ixlib=rb-1.1.0&rect=4%2C9%2C3058%2C1784&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">John Tibby</span>, <span class="license">Author provided</span></span></figcaption></figure><p>During droughts, Australia’s inland rivers dry up, leaving waterholes as the only wet places in a parched landscape. Fish, turtles, crayfish and other aquatic animals retreat to these vital refuges. </p>
<p>But our research, <a href="https://doi.org/10.1071/MF23016">published today</a>, reveals these waterholes are in danger of filling up with eroded soil from farms. This is putting a big squeeze on life in the river. </p>
<p>When drought breaks, the water flooding into the river carries soil along with it. In theory, soil deposited in waterholes could be flushed out again by large floods.</p>
<p><a href="https://www.sciencedirect.com/science/article/abs/pii/0169555X94900523">Studies in the 1990s</a> suggested as long as floods continued to occur, waterholes would maintain a natural balance of sediment. But these studies focused on the Cooper Creek, in the Kati Thanda (Lake Eyre) Basin, where waterholes have a sandy base underlying clay-dominated soil that can be easily washed out again. Many Australian rivers are different. So what happens elsewhere?</p>
<p>Our new research investigated waterhole infilling in the Moonie River, in the northern part of the Murray Darling-Basin. The Moonie catchment has experienced extensive clearing of native vegetation for sheep and cattle grazing. Unlike some neighbouring catchments, the upper and middle portions of the river have minimal water extraction and so their flow patterns are relatively “natural”. It’s a true “dryland river”, flowing only after infrequent rain events. During long periods with no flow, waterholes become the only remaining wet habitats for aquatic animals to survive.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photograph of Moonie River showing bare banks and soil erosion" src="https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531582/original/file-20230613-22-m9x1lj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Moonie River’s bare banks suffer from erosion. Much of the catchment has also been cleared for grazing.</span>
<span class="attribution"><span class="source">John Tibby</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australias-inland-rivers-are-the-pulse-of-the-outback-by-2070-theyll-be-unrecognisable-136492">Australia’s inland rivers are the pulse of the outback. By 2070, they’ll be unrecognisable</a>
</strong>
</em>
</p>
<hr>
<h2>Poking at sediment to understand waterholes</h2>
<p>Waterholes in the Moonie River can be more than 5 kilometres long, up to 5 metres deep, and teeming with life. Kingfishers, whistling kites and parrots create a symphony of sound while fish occasionally break the surface of the murky water. </p>
<p>We studied three of the deepest waterholes in the Moonie River, as they are the ones that <a href="https://www.frontiersin.org/articles/10.3389/fenvs.2021.671556/full">last longest in droughts</a>. Our initial method was simple. Using metal rods, we probed the soil’s depth at evenly spaced points along the waterholes. Our first survey revealed all three waterholes had accumulated at least a metre of soil, with one site showing more than 2.5 metres of infilling, significantly reducing its depth.</p>
<p>To determine the rate of sediment accumulation, we used radiocarbon dating. This technique is commonly used for dating objects thousands of years old such as the <a href="https://www.nma.gov.au/defining-moments/resources/mungo-lady">Lake Mungo skeletons</a>. However, nuclear weapons testing in the 1950s introduced new radioactive material including radiocarbon into the atmosphere worldwide. By analysing radiocarbon in the Moonie River sediments, we could estimate their age. </p>
<p>Our sediment dating revealed that, in places, more than two metres of soil had filled the deepest waterholes <a href="https://doi.org/10.1071/MF23016">since the 1950s</a>. Before European occupation, it would have taken thousands of years to deposit this much soil. Our research suggests sediment infilling also sped up over the past few decades.</p>
<p>The accumulated soil reduces the waterholes’ depth, preventing them from holding water for as long as they used to during droughts. Our modelling indicated this reduction has shortened the duration waterholes can hold water by almost a year at some sites, bringing them dangerously close to complete drying during the longest droughts.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A cut-away graphic showing comparing the depth of waterholes before and after European settlement" src="https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=276&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=276&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=276&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=347&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=347&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533943/original/file-20230626-5608-3zt1z7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=347&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Waterholes were much deeper before European settlement.</span>
<span class="attribution"><a class="source" href="https://ian.umces.edu/media-library/">Sara Clifford, using resources from the Integration and Application Network</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Do floods remove soil from waterholes?</h2>
<p>However, two significant questions remained: does sediment get removed after a large flood? And if it does, does material from upstream simply get dumped downstream? To answer these questions, we needed some luck and a knowledge of cocktails.</p>
<p>In 2010 and 2011, the Moonie River experienced two <a href="https://www.abc.net.au/news/2011-01-04/flood-hit-st-george-evacuates-residents/1893662">very large floods</a>. This gave us the perfect opportunity to find answers. We repeated our waterhole surveys and found even after big floods, there was still a minimum of 1 metre of sediment across most of the bottom of these waterholes, with much deeper sediment in places.</p>
<p>The missing piece of our puzzle was to determine whether the sediments were mixed together, like a margarita, and deposited by a single flood, or if they were layered, resembling a B52 cocktail (another connection to nuclear bomb testing). </p>
<p>To unravel this, we examined how the sediment had changed since before the floods. We observed distinct layers, like those in a B52 cocktail, indicating the sediments had been deposited over a series of flows and floods since the 1950s, rather than solely after individual floods.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-helped-fill-a-major-climate-change-knowledge-gap-thanks-to-130-000-year-old-sediment-in-sydney-lakes-187784">We helped fill a major climate change knowledge gap, thanks to 130,000-year-old sediment in Sydney lakes</a>
</strong>
</em>
</p>
<hr>
<h2>How can we solve this problem?</h2>
<p>We need to address the imbalance between eroded soil supply and the river’s capacity to transport sediment downstream. </p>
<p>In the Moonie River, water extraction for human use is minimal, so the problem is unlikely to lie with the river’s flow regime. The main culprit is an increased supply of sediment.</p>
<p>That means the solution lies in better catchment soil management. We need to stop so much soil washing into the Moonie River. This requires further research to find the main sources of soil that fills waterholes. Then determine the most effective ways to prevent erosion and reduce the amount of soil entering the river. This approach also helps preserve precious soils on agricultural land. In some exceptional cases, more extensive engineering solutions may be necessary to restore waterholes.</p>
<p>Given climate change projections for more frequent and longer droughts in the region, taking action to restore and preserve the function of waterholes in dryland rivers like the Moonie becomes increasingly crucial. These actions are essential for safeguarding the diverse aquatic animal life and the people that depend on waterholes for survival during droughts.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/its-official-the-murray-darling-basin-plan-hasnt-met-its-promise-to-our-precious-rivers-so-where-to-now-188074">It's official: the Murray-Darling Basin Plan hasn't met its promise to our precious rivers. So where to now?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/207155/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Tibby receives funding from the Australian Research Council, The Australian Nuclear Science and Technology Organisation, the Queensland and South Australian Governments. This research was partially funded by the Queensland Government.</span></em></p><p class="fine-print"><em><span>Jonathan Marshall works for the Queensland Department of Environment and Science who partially funded this research. </span></em></p>Australia’s beloved billabongs and waterholes are in danger of filling up with eroded soil from farms, leaving little room for the aquatic animals that depend on these vital drought refuges.John Tibby, Associate Professor in Environmental Change, University of AdelaideJonathan Marshall, Adjunct Senior Research Fellow in the Australian Rivers Institute, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1980672023-01-22T19:02:19Z2023-01-22T19:02:19ZExploding carp numbers are ‘like a house of horrors’ for our rivers. Is it time to unleash carp herpes?<figure><img src="https://images.theconversation.com/files/505286/original/file-20230119-16-v3k4oo.png?ixlib=rb-1.1.0&rect=179%2C11%2C3814%2C1982&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Ivor Stuart/The Conversation </span></span></figcaption></figure><p>With widespread La Niña flooding in the Murray-Darling Basin, common carp (<em>Cyprinus carpio</em>) populations are having a boom year. <a href="https://www.facebook.com/abccentralwest/videos/1591484014680235/?extid=NS-UNK-UNK-UNK-IOS_GK0T-GK1C&mibextid=2Rb1fB">Videos</a> of writhing masses of both adult and young fish illustrate that all is not well in our rivers. Carp now account for up to <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2427.2004.01232.x">90%</a> of live fish mass in some rivers.</p>
<p>Concerned communities are wondering whether it is, at last, time for Australia to <a href="https://www.msn.com/en-au/news/australia/european-carp-numbers-spike-after-record-flooding-calls-mount-to-push-forward-with-release-of-herpes-virus/ar-AA16uLjp">unleash the carp herpes virus</a> to control populations – but the conversation among scientists, conservationists, communities and government bodies is only just beginning.</p>
<p>Globally, the carp virus has been detected in <a href="https://www.agriculture.gov.au/sites/default/files/documents/national-carp-control-plan.pdf">more than 30 countries</a> but never in Australia. There are <a href="https://link.springer.com/article/10.1007/s10530-019-01967-1">valid concerns</a> to any future Australian release, including cleaning up dead carp, and potential significant reductions of water quality and native fish. </p>
<p>As river scientists and native fish lovers, let’s weigh the benefits of releasing the virus against the risks, set within a context of a greater vision of river recovery.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pest-plants-and-animals-cost-australia-around-25-billion-a-year-and-it-will-get-worse-164969">Pest plants and animals cost Australia around $25 billion a year – and it will get worse</a>
</strong>
</em>
</p>
<hr>
<h2>A house of horrors for rivers</h2>
<p>Carp are a pest in Australia. They cause dramatic ecological damage both here and in many countries. Carp were <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2427.2004.01232.x">first introduced</a> in the 1800s but it was only with “the Boolarra strain” that populations exploded in the basin in the early 1970s. </p>
<p>Assisted by flooding in the 1970s, carp have since invaded <a href="https://doi.org/10.1016/j.biocon.2020.108942">92%</a> of all rivers and wetlands in their present geographic range. There have been estimates of up to <a href="https://doi.org/10.1016/j.biocon.2020.108942">357 million fish</a> during flood conditions. This year, this estimate may even be exceeded. </p>
<p>Carp are super-abundant right now because floods give them access to floodplain habitats. There, each large female can spawn millions of eggs and young have high survival rates. While numbers will decline as the floods subside, the number of juveniles presently entering back into rivers will be stupendous and may last years.</p>
<p>The impacts of carp are like a house of horrors for our rivers. They cause massive degradation of aquatic plants, riverbanks and riverbeds when they feed. They alter the habitat critical for small native fish, such as southern pygmy perch. And they can make the bed of many rivers look like the surface of golf balls – denuded and dimpled, devoid of any habitat.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Dimpled riverbed" src="https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505477/original/file-20230119-22-ppme5a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Adult carp usually search for food at the bottom of rivers, stirring up sediment and creating dimples on the riverbed.</span>
<span class="attribution"><span class="source">Ivor Stuart</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/before-and-after-see-how-bushfire-and-rain-turned-the-macquarie-perchs-home-to-sludge-139919">Before and after: see how bushfire and rain turned the Macquarie perch's home to sludge</a>
</strong>
</em>
</p>
<hr>
<p>Most strikingly, this feeding behaviour contributes to turbid rivers, reducing sunlight penetration and productivity for native plants, fish and broader aquatic communities. </p>
<p>Carp truly are formidable “ecosystem engineers”, which means they directly modify their environment, much like <a href="https://theconversation.com/dont-underestimate-rabbits-these-powerful-pests-threaten-more-native-wildlife-than-cats-or-foxes-168288">rabbits</a>. Their design leads to aquatic destruction of waterways.</p>
<p>We know when their “impact threshold” exceeds <a href="https://www.publish.csiro.au/mf/pdf/MF13117">88 kilograms per hectare</a> of adult carp, we see declines in aquatic plant health, water quality, native fish numbers and other aquatic values. At present, we expect carp to far exceed this impact threshold. For river managers, the challenge is to keep numbers below that level. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Person holding a carp" src="https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505284/original/file-20230119-23-yqnz7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Carp alter the habitat critical for small native fish.</span>
<span class="attribution"><span class="source">Ivor Stuart</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The carp herpes virus</h2>
<p>The carp virus (<a href="https://link.springer.com/article/10.1186/s12985-016-0666-4">Cyprinid herpesvirus 3</a>) represents one of the only landscape-scale carp control options, although there are some exciting genetic modification technologies also emerging. </p>
<p>Mathematical modelling suggests the carp virus could cause a 40-60% knockdown for at least <a href="https://www.agriculture.gov.au/sites/default/files/documents/national-carp-control-plan.pdf">ten years</a>, which may help tip the balance in favour of native fish. Certainly, there have been some well documented <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfd.13082">virus outbreaks</a> in the United States resulting in large-scale carp deaths.</p>
<p>The risks and benefits of a potential Australian release of a carp virus are transparently addressed under the federal government’s <a href="https://www.agriculture.gov.au/biosecurity-trade/pests-diseases-weeds/pest-animals-and-weeds/national-carp-control-plan">National Carp Control Plan</a>, released last year. This plan provides some sorely needed leadership in the carp management space. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Piles of dead carp in clamshell pools" src="https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505283/original/file-20230119-15-ia7tgg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Carp account for up to 90% of live fish mass in some rivers.</span>
<span class="attribution"><span class="source">Katie Doyle</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Risks the plan identifies include:</p>
<ul>
<li>major logistic challenges in cleaning up dead carp</li>
<li>potentially serious short-term deterioration in water quality </li>
<li>potential native fish deaths due to poor water quality.</li>
</ul>
<p>On the other hand, the benefits of releasing the virus include:</p>
<ul>
<li>recovery of aquatic biodiversity populations – fish, plants and invertebrates</li>
<li>major long-term improvements to water quality </li>
<li>improved social amenity of inland waterways.</li>
</ul>
<p>As carp continue to destroy Australia’s riverine heritage, it’s time to lay our cards on the table and have a serious conversation about the carp virus. Managing expectations is a key and the confidence of stakeholders and the community is vital for its success. </p>
<p>Like rabbits and other vertebrate pests, carp are emblematic of our inability to deal with entrenched pest animals. There are no silver bullets.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australias-smallest-fish-among-22-at-risk-of-extinction-within-two-decades-144115">Australia's smallest fish among 22 at risk of extinction within two decades</a>
</strong>
</em>
</p>
<hr>
<h2>How else can we manage carp?</h2>
<p>Rolling out the carp virus is only one potential pathway away from carp. If we truly want to reduce carp numbers and impacts in the long-term then we need to examine all the roles humans play supporting them. </p>
<p>For example, the series of weir pools in the lower Murray create perfect conditions for carp because they give fish access to floodplains year round. </p>
<p>Strategically lowering and removing weir pools to re-create flowing water habitats would be one solution to help Murray cod and other flowing water specialists, such as silver perch, river snails and Murray crays. This is one of many integrated actions that could help tip the balance against carp.</p>
<p>Also, floodplain structures (which create artificial “floods”) generate static, warm-bathtub conditions that carp, being from Central Asia, prefer, contributing to huge numbers especially in dry years. Few medium or large native fish benefit from these conditions. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Flock of pelicans on a river" src="https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=388&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=388&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=388&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=488&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=488&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505285/original/file-20230119-18-3pzdvg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=488&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some native animals such as pelicans would be dining on carp in this population boom.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Another pathway is to seek guidance from increasingly sophisticated environmental modelling, which can identify optimal population trajectories for native fish over carp.</p>
<p>Now the floods have returned, we need to move away from local decisions at the site-scale and instead manage ecosystems across the entire Murray-Darling Basin. </p>
<p>The present flooding also reminds us of the <a href="https://theconversation.com/floods-can-be-a-disaster-for-humans-but-for-nature-its-boom-time-192837">huge potential increases</a> in the numbers of golden perch, frogs, yabbies and water birds. Animals that eat carp (Murray cod, golden perch, pelicans, cormorants) should all be as fat as can be. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/floods-can-be-a-disaster-for-humans-but-for-nature-its-boom-time-192837">Floods can be a disaster for humans – but for nature, it's boom time</a>
</strong>
</em>
</p>
<hr>
<h2>Looking beyond carp</h2>
<p>Just like the huge numbers of dead native fish from the <a href="https://theconversation.com/last-summers-fish-carnage-sparked-public-outrage-heres-what-has-happened-since-132346">Darling River fish kills</a> in 2018-2019, the huge numbers of carp is a big wake-up call on the <a href="https://www.publish.csiro.au/mf/mf20248">poor state</a> of rivers in the Murray-Darling Basin and how we’re managing them. </p>
<p>Perhaps what has been missing from the whole conversation is a vision for what our rivers should look like in ten or 20 years time. We don’t want to leave a legacy of degraded rivers for future Australians. </p>
<p>River health is an issue all Australian’s, country and city, need to engage with. If we don’t identify a common purpose, then we will likely continue to remain in lock-step with the great armies of carp and rivers of fish kills for generations to come. We need to do better than this. The future of our rivers depends on it.</p><img src="https://counter.theconversation.com/content/198067/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ivor Stuart is a fisheries researcher at the Gulbali Institute, Charles Sturt University. He receives funding from the Australian Government to undertake fisheries research in the Murray-Darling Basin. Ivor worked on a national carp biomass estimate as part of the National Carp Control Plan.</span></em></p><p class="fine-print"><em><span>John Koehn is an Adjunct Professor at the Gulbali Institute, Charles Sturt University. He currently receives no funding in relation from any organization in relation to this topic but has received funding for ecological research, scientific advice and population modelling for both carp and native fish in the past. </span></em></p><p class="fine-print"><em><span>Katie Doyle is a Research Scientist within the Inland Fisheries Research Group, Gulbali Institute, Charles Sturt University and receives funding from the Australian government through the Next Generation Water Management Hub to conduct research into pest fish management and the impacts of water infrastructure on freshwater ecosystems. </span></em></p><p class="fine-print"><em><span>Lee Baumgartner is the Executive Director of the Gulbali Institute at Charles Sturt University. He receives funding from the Australian government and various private donors to undertake research into fisheries sustainability in the Murray-Darling Basin and the Lower Mekong region. He also serves as leader of the Inland Fisheries Research Group and director of the Next Generation Water Management Hub.</span></em></p>Carp can make riverbeds look like golf balls – denuded and dimpled, devoid of any habitat. Releasing carp herpes virus is a controversial proposition, so let’s weigh up the risks and benefits.Ivor Stuart, Fisheries ecologist, Charles Sturt UniversityJohn Koehn, Freshwater fish ecologist, Charles Sturt UniversityKatie Doyle, Freshwater Ecologist, Charles Sturt UniversityLee Baumgartner, Professor of Fisheries and River Management, Institute for Land, Water, and Society, Charles Sturt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1959662022-12-15T19:07:19Z2022-12-15T19:07:19ZAboriginal people have spent centuries building in the Darling River. Now there are plans to demolish these important structures<figure><img src="https://images.theconversation.com/files/501221/original/file-20221215-14-ap036o.jpeg?ixlib=rb-1.1.0&rect=26%2C3%2C2525%2C1695&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Deal Lewis/AAP</span></span></figcaption></figure><p>Apart from managing the land, Indigenous people have also managed waterways, including the Murray River and the Darling/Baaka River, for thousands of years. </p>
<p>Like many Indigenous <a href="https://www.budjbim.com.au/?gclid=EAIaIQobChMInLvSl_v0-wIVRZ_CCh0RsgsEEAAYASAAEgIz8_D_BwE">peoples of Australia</a>, the Barkandji people of the Baaka manipulated and enhanced the river and floodplain ecosystems of their country.</p>
<p>Now, our <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/arco.5279">research</a> on stone, wood and earthen fish traps and fish weirs on the Baaka and its floodplains reveals how these aquatic resources were managed, grown and stored by the Barkandji.</p>
<p>These structures, and the cultural practices that sustain them, are still significant to the Barkandji people – but they’ve been severely affected by colonisation, and remain at risk from government commitments to irrigation. </p>
<h2>Reconstructing the Baaka’s Aboriginal past</h2>
<p>To study the structures in the Baaka we relied on archaeological methods, Barkandji knowledge and oral history, and written accounts from early settlers and explorers. </p>
<p>We found most of the wooden or earthen fish traps on the Baaka’s floodplains have not endured and aren’t archaeologically visible. There are, however, some existing and remnant stone traps – which were once common along the 1,200km channel. </p>
<p>These structures were encountered by explorers, ship pilots, graziers and other settlers who travelled along the Baaka between Wentworth and Bourke.</p>
<h2>The first threat to the traps were paddle steamers</h2>
<p>The first paddle steamer travelled in 1861 up the Baaka from Wentworth at the Murray-Darling junction to Brewarrina on the Barwon River. It was piloted by Captain <a href="https://en.wikipedia.org/wiki/William_Randell">William Randell</a>, and was unable to pass over the fish traps due to a lack of draught over the rocks. </p>
<p>This voyage initiated the famous paddle steamer trade that continued into the 1940s. Rocks in the river often stopped these vessels from navigating at low water levels, and they occasionally even sank. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A photo published in 1926 of the ‘P.S. Colonel’ and barges drifting downstream at Christmas Rocks.</span>
<span class="attribution"><span class="source">PRG 1258/2/2260 Godson Collection, State Library South Australia</span></span>
</figcaption>
</figure>
<p>This prompted government-resourced teams to force a passage through by blasting the rocks with dynamite. This blasted rock can still be seen at some outcrops, including areas that have the remains of fish traps or are known to have once had them. Indigenous people built new traps in these areas, often using the blasted rock.</p>
<p>During the 20th century, a series of low-level weirs were built at the small towns along the river to secure water supplies. Settlers sought the same river features to build weirs that Indigenous people did when choosing sites for stone fish traps, so many weirs were built on outcropping rock. </p>
<p>These weirs tended to have loose boulders on the downstream side to hold the weir wall in place. At Wilcannia, the Indigenous workers who carted and placed the rocks at the weir later made them into stone fish traps, which are still used today. </p>
<p>They are made in steps going up the weir wall, helping fish climb the wall like a modern fish ladder.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Wilcannia weir stone fish traps are still used by young Barkandji people.</span>
<span class="attribution"><span class="source">Sarah Martin</span></span>
</figcaption>
</figure>
<h2>Taking too much water for irrigation</h2>
<p>During the last two decades an increasing amount of water has been removed for large-scale irrigation from the Baaka and its northern tributaries. By 2019, excessive water extraction had virtually dried the Baaka and Barwon rivers from Wentworth to Collarenebri – a route more than 2,000km long. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/excessive-water-extractions-not-climate-change-are-most-to-blame-for-the-darling-river-drying-192621">Excessive water extractions, not climate change, are most to blame for the Darling River drying</a>
</strong>
</em>
</p>
<hr>
<p>The mass fish kills at Menindee in 2018–2019 showed the devastating effects of removing so many of the <a href="https://theconversation.com/the-murray-darling-basin-plan-is-not-delivering-theres-no-more-time-to-waste-91076">small to medium flows</a> that kept the ecosystem functioning. </p>
<p>This extended dry river resulted in the near extinction of many species, including river snails, mussels, catfish and silver bream. Also, without water in the river, the Barkandji could not use their fish traps or pass along knowledge of their history and significance.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dry, rocky riverbed stretches out." src="https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Baaka dried up due to excessive water extraction. Pictured here is an area at Wilcannia in 2019.</span>
<span class="attribution"><span class="source">Sarah Martin</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The New South Wales government’s response to the crisis now presents a new threat to the fragile fish traps. In 2019 the government <a href="https://legislation.nsw.gov.au/view/html/inforce/current/act-2019-016#">passed legislation</a> to fast-track new water infrastructure, despite <a href="https://www.science.org.au/supporting-science/science-policy-and-sector-analysis/reports-and-publications/fish-kills-report">strong evidence</a> it needs to reduce the amount of water allocated to irrigation. </p>
<p>The legislation enables new dams and new (higher) weirs. The old weir at Wilcannia, which has been used by Indigenous people as a series of fish traps for at least 60 years, will be partly demolished and will no longer function as a fish trap. This is despite the Indigenous community’s strong opposition. </p>
<p>The legislation also allows for the “re-establishment of natural rock weirs on the Darling River between Bourke and its junction with the Murray River”. This suggests all the rock outcrops in the Darling Baaka were originally weirs that stretched like a wall across the river and held water back (before being blasted to allow paddle steamers to pass).</p>
<p>But our field survey coupled with historical material indicates most rock outcrops were originally uneven, with openings and numerous loose rocks. This allowed water to flow through and over the rocks at different river heights, enabling the fish traps to work and helping sustain the ecosystem.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bushfire-arson-prevention-is-the-cure-11506">Bushfire arson: prevention is the cure</a>
</strong>
</em>
</p>
<hr>
<h2>How should the river be managed?</h2>
<p>Fish traps set by Aboriginal people along the Baaka offer valuable insight into how this precious body of water could be managed. The first thing is the river needs its “low and medium flows” protected.</p>
<p>Historically, Aboriginal people have held ceremonies (and to some extent still do) to mark mass migrations of fish such as golden perch and silver bream that travel upstream to spawn. These fish have to be able to travel up and down the river unimpeded. As seen at the Wilcannia weir, fish traps assist with this.</p>
<p>There are also several benefits from water flowing over and through fish trap stone walls. The walls increase flow turbulence, reduce silting, improve water quality and are “keyed” to let small fish through. They also provide a rocky habitat that effectively forms “multi-storey apartments” for invertebrates such as yabbies and river snails.</p>
<p>Stone fish traps are also often found in association with shallow aquifer springs, with one recorded trap built around a spring. This is evidence of fish management; the fresh spring water attracts fish and acts as a refuge during drought.</p>
<p>Local Indigenous people also understand the necessity of regularly filling floodplain lakes, swamps and billabongs. They previously enhanced these water bodies by using temporary wooden and earthen weirs – providing fish reserves, fish nurseries and rich and diverse habitats for aquatic life.</p>
<p>These structures kept aquatic plants and animals safe to seed the river with life when floods came down after dry periods. They held water to replenish the shallow aquifers that create springs and soaks in the river.</p>
<p>Water managers have so far largely ignored the potential for Indigenous knowledge to facilitate the sustainable management of the Baaka. Yet Indigenous people living along the Baaka have known about how its water moves long before scientists did.</p>
<p>The NSW government’s proposed infrastructure will not only endanger the remnants of culturally significant fish trap structures, but also impact the river’s ecology. Unless Indigenous people’s experience and knowledge are taken seriously, the Baaka and its precious resources may be depleted beyond the point of saving.</p>
<hr>
<p><em>Acknowledgment: we would like to thank our colleague Sarah Martin, who led the research paper this article is based on, and whose contributions were invaluable in gathering these findings.</em></p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/m_c5DvmyN28?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p class="fine-print"><em><span>Michael Westaway receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Sue Jackson receives funding from the Australian Research Council and the Commonwealth Government's Murray Darling Basin Water and Environment Program. Sue is a member of the Murray Darling Basin Authority's scientific advisory committee.</span></em></p><p class="fine-print"><em><span>Badger Bates does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Indigenous engineering and care for Country points to a better way to manage the Baaka.Michael Westaway, Australian Research Council Future Fellow, Archaeology, School of Social Science, The University of QueenslandBadger Bates, Indigenous knowledge holder, Indigenous KnowledgeSue Jackson, Professor, Australian Rivers Institute, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1657642021-08-11T05:04:58Z2021-08-11T05:04:58ZThe Murrumbidgee River’s wet season height has dropped by 30% since the 1990s — and the outlook is bleak<figure><img src="https://images.theconversation.com/files/415597/original/file-20210811-19-j3o2gq.jpeg?ixlib=rb-1.1.0&rect=19%2C11%2C2636%2C1979&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Murrumbidgee River, near Yass</span> <span class="attribution"><span class="source">Nick Pitsas, CSIRO/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The Murray-Darling Basin is Australia’s biggest agricultural region, producing <a href="https://doi.org/10.1016/j.ecoser.2015.02.008">almost 40%</a> of the national food supply during the growing season from April to September. It’s filled with criss-crossing rivers, wetlands and lakes farmers rely on for crops, and it’s home to a range of freshwater wildlife, many of which are under threat. </p>
<p>But <a href="https://www.nature.com/articles/s41598-021-95531-4">our new research</a> found climate change since the 1990s has drastically reduced the amount of water available in the southern part of the basin. </p>
<p>The height of the Murrumbidgee River — the third longest in Australia and highly valued for irrigation and hydro-electricity — has dropped by about 30% during the growing season. This is a loss of approximately 300 million litres per day that would normally flow past Wagga Wagga, New South Wales — the same as <a href="http://urbanwater.melbourne.vic.gov.au/melbournes-water-story/water-use-facts/">six days of water use</a> in the City of Melbourne.</p>
<p>The findings follow <a href="https://theconversation.com/this-is-the-most-sobering-report-card-yet-on-climate-change-and-earths-future-heres-what-you-need-to-know-165395">a major report</a> the Intergovernmental Panel on Climate Change released on Monday, which <a href="https://theconversation.com/climate-change-has-already-hit-australia-unless-we-act-now-a-hotter-drier-and-more-dangerous-future-awaits-ipcc-warns-165396">found</a> much of Australia will become more arid as the world warms. This will bring reduced river flows, mass tree deaths, more droughts and drier soils.</p>
<p>The viability of the basin is at stake. Continued drying and warming in Australia will cause water availability to decline even further, deepening the hurt for communities, businesses, animals and the environment. Any decisions about the competing interests of agriculture and the environment must keep these global warming impacts front of mind. </p>
<h2>What we found</h2>
<p>The southern Murray-Darling Basin occupies the southern half of NSW and northern Victoria. It receives most of its water from rain in the cooler months that fills dams, with any overflow spilling into the floodplains. </p>
<p>But our research shows rainfall in April to May has <a href="https://doi.org/10.1038/s41598-021-95531-4">significantly decreased</a> which, in turn, has caused the net inflows to the Murrumbidgee River catchment in the southern basin to decrease. This includes in the main dams of Burrinjuck and Blowering in the upper part of the catchment, and downstream river heights. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415599/original/file-20210811-17-11oinej.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Murrumbidgee River catchment makes up 8% of the Murray-Darling Basin.</span>
<span class="attribution"><span class="source">Conquimbo/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The <a href="https://www.industry.nsw.gov.au/water/basins-catchments/snapshots/murrumbidgee#:%7E:text=Catchment%20area,metres%20on%20the%20western%20plains.">Murrumbidgee River catchment</a> is approximately 84,000 square kilometres, or about 8% of the basin. It encompasses a complex series of wetlands and floodplains, and supplies water for homes in many communities, including Wagga Wagga, Griffith and Leeton. </p>
<p>Using statistical analysis and machine learning, we found the Murrumbidgee River dropped from 3.5 metres in 1990 to 2.5 metres in 2019 during the cooler months. When you multiply this by the the length and breadth of the river, which stretches <a href="https://www.mdba.gov.au/water-management/catchments/murrumbidgee">more than 1,400km</a>, this is an enormous volume of water lost.</p>
<p>Given this drop is associated with the wettest months from April to September, the outlook for the warmer months between October and March is dismal. The number of days when the river ceases to flow will certainly increase.</p>
<h2>Long, difficult droughts</h2>
<p>Dam building and excessive irrigation <a href="https://newsroom.unsw.edu.au/news/science-tech/long-term-study-murray-darling-basin-wetlands-reveals-impact-dams">are often behind</a> decreased river flows across the Murray-Darling Basin. But in this case, we can point to decreased rainfall from climate change as the reason the Murrumbidgee River catchment is losing water.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-looked-at-35-years-of-rainfall-and-learnt-how-droughts-start-in-the-murray-darling-basin-145766">We looked at 35 years of rainfall and learnt how droughts start in the Murray-Darling Basin</a>
</strong>
</em>
</p>
<hr>
<p>The Burrinjuck Dam was <a href="https://portal.engineersaustralia.org.au/heritage/burrinjuck-dam-no-1-power-station-murrumbidgee-river-1928">completed in 1928</a> and the <a href="https://www.waternsw.com.au/supply/heritage/dam-histories#:%7E:text=Blowering%20Dam%20history&text=It%20was%20built%20in%20the,a%20nearby%20property%2C%20Blowering%20Station.">Blowering Dam</a> was completed in the 1960s. Until the early 1990s, the Murrumbidgee River used to regularly spill over the banks at Wagga Wagga and also further downstream at Hay, during the cool seasons. </p>
<p>Likewise, we didn’t identify irrigation as a major contributor, because more than 80% of irrigation occurs downstream of Wagga Wagga. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415593/original/file-20210811-25-13yvzb5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Murrumbidgee River is over 1,400 kilometres long, and flows past Wagga Wagga.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Global warming has accelerated in the latter half of last century, and particularly <a href="https://bom.gov.au/state-of-the-climate/">since the 1990s</a> in Australia. </p>
<p>To see its effect in Australia, we need only look to the extended <a href="http://www.bom.gov.au/climate/current/statements/scs70.pdf">drought conditions</a> since the mid-1990s in the basin, comprising the Millennium Drought (1997-2009) and the 2017-2019 drought. They were extreme, even compared to the historical Federation Drought between 1895 and 1903.</p>
<p>In 2006, the Australian newspaper <a href="https://www.mdba.gov.au/publications/mdba-reports/sharing-water-100-years-river-murray-politics">reported that inflows</a> to the nearby River Murray system between June and November were 610 gigalitres, “just 56 percent of the previously recorded low in 1902” when the Federation Drought was at its worst.</p>
<h2>Climate change exacerbates dry years</h2>
<p>But climate change doesn’t tell the whole story, there are also other factors at play driving the <a href="https://doi.org/10.1002/joc.1627">low rainfall trend</a> in the basin. Namely, <a href="https://theconversation.com/why-drought-busting-rain-depends-on-the-tropical-oceans-132188">natural climate phenomena</a> form over the ocean and bring wetter or drier weather to various parts of Australia.</p>
<p>One of these climate phenomena is the Indian Ocean Dipole (IOD), which brings wetter weather than normal from June to October when in its “negative” phase (in fact, the Bureau of Meteorology <a href="https://theconversation.com/a-wet-winter-a-soggy-spring-what-is-the-negative-indian-ocean-dipole-and-why-is-it-so-important-164957">recently declared</a> another negative IOD for Australia this year, the first in five years). </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-wet-winter-a-soggy-spring-what-is-the-negative-indian-ocean-dipole-and-why-is-it-so-important-164957">A wet winter, a soggy spring: what is the negative Indian Ocean Dipole, and why is it so important?</a>
</strong>
</em>
</p>
<hr>
<p>But in the last two decades there have been only <a href="https://doi.org/10.1029/2008GL036801">two strongly</a> negative-phase Indian Ocean Dipole (IOD) events affecting Australia. The current IOD phase is only moderately negative. </p>
<p>Climate drivers like this are entirely natural and have been occurring for thousands of years, but human-caused climate change exacerbates their influence. Generally, it makes dry seasons drier, and wet seasons wetter.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415596/original/file-20210811-17-1pjjbam.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">After years of little rain or snowmelt, evaporation accentuates the lack off run-off.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>In April this year, <a href="https://theconversation.com/sydneys-disastrous-flood-wasnt-unprecedented-were-about-to-enter-a-50-year-period-of-frequent-major-floods-158427">devastating floods</a> engulfed western Sydney. This resulted in the <a href="https://www.dailyadvertiser.com.au/story/7349512/flood-alert-for-murrumbidgee-river-from-rainfall-and-full-dams/">dams reaching nearly 100% capacity</a> last month. However, the river height at Wagga Wagga is currently <a href="https://realtimedata.waternsw.com.au/">around 5.3m</a> and this is still 2m below the minor flood level of 7.3m — too low to overflow into the surrounding floodplain. </p>
<p>And after years of little rain or snowmelt, evaporation accentuates the lack off run-off into dams and streams, because water needs to soak into dry catchments before significant run-off can occur. </p>
<h2>Profoundly disturbing implications</h2>
<p>The implications of our research are profoundly disturbing, because it means the economic, social and ecological sustainability of the Murrumbidgee River catchment is at stake. </p>
<p>Under climate change, we can expect further drying of wetlands and major losses of wildlife habitat. For example, the mid-Murrumbidgee and the Lowbidgee wetlands are listed as <a href="https://www.environment.gov.au/water/cewo/catchment/murrumbidgee">nationally significant</a>, providing critical habitat for threatened frogs, such as the <a href="https://www.environment.gov.au/biodiversity/threatened/recovery-plans/national-recovery-plan-southern-bell-frog-litoria-raniformis">vulnerable southern bell frog</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=555&fit=crop&dpr=1 754w, https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=555&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/415600/original/file-20210811-19-2ztr0j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=555&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The southern bell frog is threatened by habitat loss and degradation, barriers to movement, predation, disease and exposure to biocides.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>For farmers and communities, we can expect huge reductions in the amount of water allocated for irrigation. The ability for communities to survive these severe decreases in agricultural productivity will be tested.</p>
<p>The efficiency of farm practices is improving. But because of the continuing threat of drought conditions in a warming climate, there’s an urgent need to plan for further decreases in rainfall, and further unreliability of water supply. </p>
<p>Australia needs a <a href="https://theconversation.com/5-ways-the-government-can-clean-up-the-murray-darling-basin-plan-116265">new review</a> of water availability and sustainability in the Murrumbidgee and other river systems in the southern Murray-Darling Basin.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-has-already-hit-australia-unless-we-act-now-a-hotter-drier-and-more-dangerous-future-awaits-ipcc-warns-165396">Climate change has already hit Australia. Unless we act now, a hotter, drier and more dangerous future awaits, IPCC warns</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/165764/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>During the warmer months, the number of days when the river ceases to flow will increase. Climate change is to blame.Milton Speer, Visiting Fellow, School of Mathematical and Physical Sciences, University of Technology SydneyLance M Leslie, Professor, School of Mathematical And Physical Sciences, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1551162021-02-11T04:18:04Z2021-02-11T04:18:04ZOur national water policy is outdated, unfair and not fit for climate challenges: major new report<figure><img src="https://images.theconversation.com/files/383672/original/file-20210211-19-15a153.jpg?ixlib=rb-1.1.0&rect=0%2C13%2C2940%2C1944&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Most Australians know all too well how precious water is. Sydney just experienced a <a href="https://www.sydneywater.com.au/SW/about-us/our-publications/Media/have-no-doubt--we-re-in-drought/index.htm">severe drought</a>, while towns across New South Wales and Queensland <a href="https://www.9news.com.au/national/queensland-floods-warwick-two-years-worth-rain-weather-drought-news-australia/75f626e9-7f66-4078-b36e-720cfe0de0f8">ran out of drinking water</a>. Under climate change, the situation will become more dire, and more common. </p>
<p>It wasn’t meant to be this way. In 2004, federal, state and territory governments signed up to the <a href="https://www.agriculture.gov.au/sites/default/files/sitecollectiondocuments/water/Intergovernmental-Agreement-on-a-national-water-initiative.pdf">National Water Initiative</a>. It was meant to secure Australia’s water supplies through better governance and plans for sustainable use across industry, environment and the community.</p>
<p>But a report by the <a href="https://www.pc.gov.au/inquiries/current/water-reform-2020/draft">Productivity Commission</a> released today says the policy must be updated. It found the National Water Initiative is not fit for the challenges of climate change, a growing population and our changing perceptions of how we value water. </p>
<p>The report’s findings matter to all Australians, whether you live in a city or a drought-ravaged town. If governments don’t manage water better, on our behalf, then entire communities may disappear. Agriculture will suffer and nature will continue to degrade. It’s time for a change.</p>
<h2>A big job ahead</h2>
<p>The report acknowledges progress in national water reform, and says Australia’s allocation of water resources has improved. But the commission makes clear there’s still much to be done, including:</p>
<ul>
<li><p>making water infrastructure projects a critical part of the National Water Initiative</p></li>
<li><p>explicitly recognising how climate change threatens water-sharing agreement between states, users, towns, agriculture and the environment</p></li>
<li><p>more meaningful recognition of Indigenous rights to water</p></li>
<li><p>delivering adequate drinking water quality to all Australians, including those in regional and remote communities, especially during drought</p></li>
<li><p>all states committing to drought management plans.</p></li>
</ul>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/rlaPnaGk7S8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Why Australia needs National Water Reform.</span></figcaption>
</figure>
<h2>Busting water illusions</h2>
<p>The commission’s proposal to make water infrastructure developments a much larger part of the National Water Initiative is a critical way to keep governments honest. </p>
<p>For years, state and federal governments have used taxpayers’ dollars to pay for <a href="https://www.lexology.com/library/detail.aspx?g=4ad1c8f5-0436-4e8f-b3ce-64be2fb2149f">farming water infrastructure</a> that largely benefits <a href="https://apo.org.au/node/262286">the big end of town</a> — large, corporate irrigators. </p>
<p>For example, the federal government last year announced an additional A$2 billion for its “<a href="https://minister.infrastructure.gov.au/mccormack/media-release/budget-2020-building-21st-century-water-infrastructure">Building 21 Century Water infrastructure</a>” project. This type of funding represents a return to schemes like the discredited <a href="https://www.abc.net.au/news/2019-11-01/bradfield-scheme-is-moving-water-from-north-to-south-feasible/11662942">Bradfield</a> scheme, a plan to redirect floodwater from Queensland’s north to the south, including to South Australia. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australias-inland-rivers-are-the-pulse-of-the-outback-by-2070-theyll-be-unrecognisable-136492">Australia’s inland rivers are the pulse of the outback. By 2070, they’ll be unrecognisable</a>
</strong>
</em>
</p>
<hr>
<p>Such <a href="https://www.abc.net.au/news/2019-11-01/bradfield-scheme-is-moving-water-from-north-to-south-feasible/11662942">megaprojects</a>, even when relabelled or reconceived, perpetuate simplistic myths of the early 20th Century that Australia – the driest inhabited continent on Earth – can be “<a href="https://www.theguardian.com/commentisfree/2019/sep/25/we-are-talking-about-drought-proofing-again-they-are-simplistic-solutions-that-will-destroy-australia">drought-proofed</a>”.</p>
<p>As the report highlights, when governments in 2004 signed up to the <a href="https://www.agriculture.gov.au/sites/default/files/sitecollectiondocuments/water/Intergovernmental-Agreement-on-a-national-water-initiative.pdf">National Water Initiative</a>, they agreed to ensure investments in water infrastructure would be both economically viable and ecologically sustainable. But many proposed water infrastructure projects <a href="https://waterjusticehub.org/submission-by-the-australian-national-universitys-institute-for-water-futures-to-the-productivity-commissions-national-water-reform-inquiry/">appear to be neither</a>.</p>
<p>This includes the construction of <a href="https://www.waternsw.com.au/projects/new-dams-for-nsw/dungowan-dam">Dungowan Dam in NSW</a>. For this dam, the commission notes, “any infrastructure that improves reliability for one user will affect water availability for others” and the “prospect of ‘new’ water is illusory”.</p>
<p>The commission warned projects that are not economically viable or ecologically sustainable can “burden taxpayers with ongoing costs, discourage efficient water use and result in long-lived impacts on communities and the environment”. </p>
<p>Equally disturbing is that billions of dollars for water infrastructure are currently targeted primarily for primary industry (such as agriculture and mining) while communities in desperate need of drinking water that meets water quality guidelines <a href="https://www.tandfonline.com/doi/full/10.1080/07900627.2019.1685950">miss out</a>. Thousands of Australians in more remote communities still <a href="https://www.tandfonline.com/doi/full/10.1080/07900627.2019.1685950">lack access</a> to drinking water most Australians take for granted. </p>
<h2>Water scarcity under climate change</h2>
<p>Water availability under climate change features prominently in the report. The commission says droughts will likely become more intense and frequent and in many places, water will become scarce.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/to-help-drought-affected-farmers-we-need-to-support-them-in-good-times-as-well-as-bad-101184">To help drought-affected farmers, we need to support them in good times as well as bad</a>
</strong>
</em>
</p>
<hr>
<p>The report says planning provisions were inadequate to deal with both the Millennium Drought and the <a href="https://www.smh.com.au/environment/sustainability/barwon-darling-river-faces-collapse-from-government-mistakes-report-20190724-p52a7i.html">recent drought</a> in Eastern Australia. </p>
<p>The commission also said more work is needed to rebalance water use in response to climate change. One need only look to the 2012 Murray-Darling Basin Plan — one of the key outcomes of the National Water Initiative — which didn’t <a href="https://www.sciencedirect.com/science/article/abs/pii/S146290112030215X?dgcid=rss_sd_all">account for climate change</a> when determining how much water to take from streams and rivers.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Aerial view of a wetland in the Murray-Darling Basin" src="https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383673/original/file-20210211-15-m3zobr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Thousands of Australians lack access to drinking water.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Overcoming past failures</h2>
<p>As the commission report notes, one key policy failure since the 2004 National Water Initiative was signed was the federal government’s <a href="https://www.abc.net.au/news/rural/2014-05-13/budget-water/5430960">dismantling of the National Water Commission</a> in 2015. It meant Australia no longer had a resourced, well-informed agency to “mark the homework” and make sure the reforms were being implemented as agreed.</p>
<p>The report offers ways to overcome a range of past policy water failures, including strengthening governance architecture for the National Water Initiative.</p>
<p>Importantly, the report also called for better recognition of the rights Aboriginal and Torres Strait Islander people hold over water. </p>
<p>Aboriginal communities and corporations own <a href="https://theconversation.com/australia-has-an-ugly-legacy-of-denying-water-rights-to-aboriginal-people-not-much-has-changed-141743">just 0.1%</a> of the more than A$26 billion of water entitlements in the Murray-Darling Basin. Clearly, such gross inequities must be overcome.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Dried-up river in the Basin" src="https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383678/original/file-20210211-24-1emv55m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The report calls for more meaningful recognition of Indigenous rights to water.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>What happens in the Murray-Darling Basin is key to national water reform. There is overwhelming evidence the <a href="https://www.theguardian.com/environment/2018/feb/05/murray-darling-basin-plan-fails-environment-and-wastes-money-experts">basin plan needs fixing</a>. </p>
<p><a href="https://murraydeclaration.org/the-declaration">To start</a>, subsidies for irrigation-related water infrastructure should be halted until a comprehensive audit is conducted to determine who gets water, when and how. And an independent, properly funded expert agency should be established to monitor, advise and implement the <a href="https://www.legislation.gov.au/Details/C2017C00151">law for managing</a> the Basin’s water resources. </p>
<p>The <a href="https://www.environment.sa.gov.au/topics/river-murray-new/basin-plan/murray-darling-basin-commission">800-page report</a> of the 2019 South Australia Murray-Darling Royal Commission proposes many ways forward. Yet unfortunately, that substantial body of work is not mentioned in the Productivity Commission’s report.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-has-an-ugly-legacy-of-denying-water-rights-to-aboriginal-people-not-much-has-changed-141743">Australia has an ugly legacy of denying water rights to Aboriginal people. Not much has changed</a>
</strong>
</em>
</p>
<hr>
<h2>We’re still waiting for change</h2>
<p>In 2007, the worst year of the Millennium Drought, <a href="https://apo.org.au/node/262286">Prime Minister John Howard</a> said the current trajectory of water use and management in Australia was not sustainable. He said:</p>
<blockquote>
<p>In a protracted drought, and with the prospect of long-term climate change, we need radical and permanent change.</p>
</blockquote>
<p>We are still waiting for that change. If Australia is to be prosperous and liveable into the future, governments must urgently implement water reform – including adopting recommendations from the Productivity Commission’s report. </p>
<p>If it fails to act, our landscapes will degrade, agriculture will become unsustainable, communities will disintegrate and First Peoples will continue to suffer water injustice.</p><img src="https://counter.theconversation.com/content/155116/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Quentin Grafton is affiliated with the Institute for Water Futures (IWF) at the Australian National University. The IWF made a submission to the Productivity Commission in August 2020 in relation to its inquiry into National Water Reform. He is an Australian Research Council Laureate Fellow and is currently leading a project on water justice and resilience.</span></em></p>A major new report from the Productivity Commission calls for an overhaul of Australia’s 17-year-old policy on water.Quentin Grafton, Director of the Centre for Water Economics, Environment and Policy, Crawford School of Public Policy, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1457662020-09-24T19:59:22Z2020-09-24T19:59:22ZWe looked at 35 years of rainfall and learnt how droughts start in the Murray-Darling Basin<p>The <a href="https://www.agriculture.gov.au/abares/publications/insights/effects-of-drought-and-climate-variability-on-Australian-farms">extreme, recent drought</a> has devastated many communities around the Murray-Darling Basin, but the processes driving drought are still not well understood. </p>
<p>Our <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL090238">new study</a> helps to change this. We threw a weather model into reverse and ran it back for 35 years to study the natural processes leading to low rainfall during drought.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/morrison-government-plan-to-scrap-water-buybacks-will-hurt-taxpayers-and-the-environment-145613">Morrison government plan to scrap water buybacks will hurt taxpayers and the environment</a>
</strong>
</em>
</p>
<hr>
<p>And we found the leading cause for drought in the Murray-Darling Basin was that moisture from oceans didn’t reach the basin as often as normal, and produced less rain when it did. In fact, when moisture from the ocean did reach the basin during drought, the parched land surface actually made it harder for the moisture to fall as rain, worsening the already dry conditions.</p>
<p>These findings can help resolve why climate models struggle to simulate drought well, and ultimately help improve our ability to predict drought. This is crucial for our communities, farmers and bushfire emergency services.</p>
<h2>There’s still a lot to learn about rain</h2>
<p>The most recent drought was relentless. It saw the <a href="http://www.bom.gov.au/climate/current/statements/scs70.pdf">lowest rainfall on record</a> in the Murray-Darling Basin, <a href="https://www.abs.gov.au/websitedbs/D3310114.nsf/home/ABS+Chief+Economist+-+Measuring+natural+disasters+in+the+Australian+economy">reduced</a> agricultural output, led to increased food prices, and created tinder dry conditions before the <a href="https://blogs.scientificamerican.com/observations/australias-angry-summer-this-is-what-climate-change-looks-like/">Black Summer</a> fires.</p>
<p>Drought in the Murray-Darling Basin is associated with global climate phenomena that drive changes in ocean and atmospheric circulation. These climate drivers include the <a href="http://www.bom.gov.au/climate/about/?bookmark=enso">El Niño and La Niña</a> cycle, the <a href="http://www.bom.gov.au/climate/about/?bookmark=iod">Indian Ocean Dipole</a> and the <a href="http://www.bom.gov.au/climate/about/?bookmark=sam">Southern Annular Mode</a>. </p>
<p>Each influences the probability of rainfall over Australia. But drivers like El Niño can only explain <a href="https://journals.ametsoc.org/mwr/article/137/10/3233/70705/On-the-Remote-Drivers-of-Rainfall-Variability-in">around 20%</a> of Australian rainfall — they only tell part of the story. </p>
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Read more:
<a href="https://theconversation.com/yes-its-been-raining-a-lot-but-that-doesnt-mean-australias-drought-has-broken-144702">Yes, it's been raining a lot – but that doesn't mean Australia's drought has broken</a>
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<p>To fully understand the physical processes causing droughts to begin, persist and end, we need to answer the question: where does Australia’s rainfall come from? It may seem basic, but the answer isn’t so simple. </p>
<h2>Where does Australia’s rainfall come from?</h2>
<p>Broadly, scientists know rainfall derives from evaporation from two main sources: the ocean and the land. But we don’t know exactly where the moisture supplying Australia’s rainfall originally evaporates from, how the moisture supply changes between the seasons nor how it might have changed in the past. </p>
<p>To find out, we used a <a href="https://climatechange.environment.nsw.gov.au/Climate-projections-for-NSW/About-NARCliM">sophisticated model</a> of Australia’s climate that gave data on atmospheric pressure, temperature, humidity, winds, rainfall and evaporation. </p>
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Read more:
<a href="https://theconversation.com/arent-we-in-a-drought-the-australian-black-coal-industry-uses-enough-water-for-over-5-million-people-137591">Aren't we in a drought? The Australian black coal industry uses enough water for over 5 million people</a>
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<p>We put this data into a “<a href="https://journals.ametsoc.org/jcli/article/33/20/8721/353895/Australian-Precipitation-Recycling-and-Evaporative">back-trajectory model</a>”. This traced the path of water from where it fell as rain, backwards in time through the atmosphere, to uncover where the water originally evaporated from. We did this for every day it rained over Australia between 1979 and 2013.</p>
<p>Not surprisingly, we found more than three-quarters of rain falling in Australia comes from evaporation from the surrounding oceans. So what does this mean for the Murray-Darling Basin?</p>
<h2>Up to 18% of rain in the basin starts from the land</h2>
<p>During the Millennium Drought and other big drought years (such as in 1982), the Murray-Darling Basin heavily relied on moisture transported from the Tasman and Coral seas for rain. Moisture evaporated off the east coast needs easterly winds to transport it over the Great Dividing Range and into the Murray-Darling Basin, where it can form rain. </p>
<p>This means low rainfall during these droughts was a result of anomalies in atmospheric circulation, which prevented the easterly flow of ocean moisture. The droughts broke when moisture could once again be transported into the basin. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/359721/original/file-20200924-18-g39c8w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A lack of vegetation on the land can exacerbate drought.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>The Murray-Darling Basin was also one of the regions in Australia where most “<a href="http://onlinelibrary.wiley.com/doi/10.1029/96RG01927/abstract">rainfall recycling</a>” happens. This is when, following rainfall, high levels of evaporation from soils and plants return to the atmosphere, sometimes leading to more rain – particularly in spring and summer.</p>
<p>This means if we change the way we use the land or the vegetation, there is a risk we could impact rainfall. <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/hyp.3360090512">For example</a>, when a forest of tall trees is replaced with short grass or crops, humidity can go down and wind patterns change in the atmosphere above. Both of these affect the likelihood of rain.</p>
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Read more:
<a href="https://theconversation.com/6-000-years-of-climate-history-an-ancient-lake-in-the-murray-darling-has-yielded-its-secrets-133685">6,000 years of climate history: an ancient lake in the Murray-Darling has yielded its secrets</a>
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<p>In the northern part of the basin, less evaporation from the dry land surface exacerbated the low rainfall. </p>
<p>On the other hand, when the drought broke, more moisture evaporated from the damp land surface, adding to the already high levels of moisture coming from the ocean. This meant the region got a surplus of moisture, promoting even more rain. </p>
<p>This relationship was weaker in the southern part of the basin. But interestingly, rainfall there relied on moisture originating from evaporation in the northern basin, particularly during drought breaks. This is a result we need to explore further.</p>
<h2>Summer rain not so good for farmers</h2>
<p>Rainfall and moisture sources for Australia and the Murray-Darling Basin are changing. In the past 35 years, the southeast of the country has been receiving less moisture in winter, and more in summer. </p>
<p>This is likely due to increased easterly wind flows of moisture from the Tasman Sea in summer, and reduced westerly flows of moisture from the Southern Ocean in winter. </p>
<p>This has important implications, particularly for agriculture and water resource management.</p>
<p>For example, more rainfall in summer can be a problem for horticultural farms, as it can make crops more <a href="https://industry.australianalmonds.com.au/wp-content/uploads/2018/07/Pest-Disease-Disease-1-Managing-Rust-in-Almonds-HR.pdf">susceptible to fungal diseases</a>, <a href="https://insights.osu.edu/food/wine-grape-weather">decreases the quality of wine grape crops</a> and affects harvest scheduling. </p>
<p>Less winter rain also means <a href="https://www.mdba.gov.au/discover-basin/landscape/climate">less runoff</a> into creeks and rivers — a vital process for mitigating drought risk. And this creates uncertainty for dam operators and water resource managers.</p>
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Read more:
<a href="https://theconversation.com/need-a-mood-lift-weve-tracked-4-ways-australias-environment-has-repaired-itself-in-2020-144949">Need a mood lift? We’ve tracked 4 ways Australia’s environment has repaired itself in 2020</a>
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<p>Understanding where our rainfall comes from matters, because it can improve weather forecasts, seasonal streamflow forecasts and long-term rainfall impacts of climate change. For a drought-prone country like Australia — set to worsen under a changing climate — this is more crucial than ever.</p><img src="https://counter.theconversation.com/content/145766/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chiara Holgate receives funding from the Australian National University. </span></em></p><p class="fine-print"><em><span>Albert Van Dijk receives or has previously received funding from several government-funded agencies, grant schemes and programmes.</span></em></p><p class="fine-print"><em><span>Jason Evans receives or has previously received funding from the Australian Research Council, The National Environmental Science Program and the NSW DPIE.</span></em></p>To fully understand why droughts begin, persist and end, we need to answer the question: where does Australia’s rainfall come from? It may seem basic, but the answer isn’t so simple.Chiara Holgate, Hydrologist & PhD Candidate, Australian National UniversityAlbert Van Dijk, Professor, Water and Landscape Dynamics, Fenner School of Environment & Society, Australian National UniversityJason Evans, Professor, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1417432020-07-24T02:03:21Z2020-07-24T02:03:21ZAustralia has an ugly legacy of denying water rights to Aboriginal people. Not much has changed<figure><img src="https://images.theconversation.com/files/349041/original/file-20200723-32-1ml9k9b.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4961%2C3304&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Water management in the Murray-Darling Basin has radically changed over the past 30 years. But none of the changes have addressed a glaring injustice: Aboriginal people’s share of water rights is minute, and in New South Wales it is diminishing.</p>
<p>In the 1990s, governments tried to restore the health of rivers in the basin by <a href="https://www.mdba.gov.au/sites/default/files/archived/cap/SETTING_THE_CAP.pdf">limiting</a> how much water could be extracted. They also separated land and water titles to enable farmers to trade water. </p>
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Read more:
<a href="https://theconversation.com/aboriginal-voices-are-missing-from-the-murray-darling-basin-crisis-110769">Aboriginal voices are missing from the Murray-Darling Basin crisis</a>
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<p>This allowed the recovery of water for the environment and led to the world’s biggest water market, now worth <a href="https://daff.ent.sirsidynix.net.au/client/en_AU/search/asset/1027121/2">billions of dollars</a>. For a range of reasons, Aboriginal people have largely been shut out of this valuable water market.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0264837719319799">Our research</a>, the first of its kind, shows Aboriginal water entitlements in the Murray-Darling Basin are declining, and further losses are likely under current policies. This water injustice is an ongoing legacy of colonisation.</p>
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<a href="https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A shallow river cuts through brown land, beside a gum tree." src="https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/349060/original/file-20200723-22-imvure.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Aboriginal people have largely been shut out of the market.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<h2>An unjust distribution of water</h2>
<p>A water use right, also called a licence or entitlement, grants its holder a share of available water in a particular waterway. Governments allocate water against these entitlements periodically, <a href="https://www.mdba.gov.au/sites/default/files/attachments/basin-plan-rollout/1113_planning-assumptions_allocation-vs-usage.jpg">depending on rainfall and water storage</a>. Entitlement holders choose how to use this water. Typically, they extract it for purposes such as irrigation, or sell it on the temporary market.</p>
<p>We mapped Aboriginal water access and rights in NSW over more than 200 years, including the current scale of Aboriginal-held water entitlements.</p>
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Read more:
<a href="https://theconversation.com/water-in-northern-australia-a-history-of-aboriginal-exclusion-60929">Water in northern Australia: a history of Aboriginal exclusion</a>
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<p>Across ten catchments in the NSW portion of the Murray-Darling Basin, Aboriginal people collectively hold just 12.1 gigalitres of water. This is a mere 0.2% of all available surface water (as of October 2018).</p>
<p>By comparison, Aboriginal people make up 9.3% of this area’s population. </p>
<p>The value of water held by Aboriginal organisations was A$16.5 million in 2015-16 terms, equating to just 0.1% of the value of the Murray-Darling Basin’s water market.</p>
<p>We wanted to understand how these limited water rights affect Aboriginal people today, and the challenges, if any, they face in holding onto these entitlements. This required examining Australia’s water history and its systems of water rights distribution.</p>
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Read more:
<a href="https://theconversation.com/no-water-no-leadership-new-murray-darling-basin-report-reveals-states-climate-gamble-136514">No water, no leadership: new Murray Darling Basin report reveals states' climate gamble</a>
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<p>What we found were key moments when governments denied Aboriginal people water rights and, by extension, the benefits that now flow from water access. This includes the ability to use water for an agricultural enterprise, or to temporarily trade water as many other entitlement holders do. We describe these moments as waves of dispossession.</p>
<h2>The first wave of dispossession</h2>
<p>Under colonial water law, rights to use water, for example for farming, were granted to whoever owned the land where rivers flowed. This link between water use and land-holding remained in place <a href="https://theconversation.com/water-in-northern-australia-a-history-of-aboriginal-exclusion-60929">until the end of the 20th century</a>. </p>
<p>As a result, Aboriginal people, whose traditional ownership of land (native title) was only recognised by the Australian High Court in 1992, were largely denied legal rights to water.</p>
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<img alt="" src="https://images.theconversation.com/files/346519/original/file-20200709-50-160bopt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/346519/original/file-20200709-50-160bopt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/346519/original/file-20200709-50-160bopt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/346519/original/file-20200709-50-160bopt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/346519/original/file-20200709-50-160bopt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/346519/original/file-20200709-50-160bopt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/346519/original/file-20200709-50-160bopt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Water entitlements held by Aboriginal by catchment in the NSW portion of the MDB (as at October 2018)</span>
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<h2>The second wave</h2>
<p>During the last quarter of the 20th century, governments introduced land restitution measures, such as the NSW Aboriginal Land Rights Act (1983), to redress or compensate Indigenous peoples for colonial acts of dispossession.</p>
<p>We found water entitlements were attached to some of the land parcels that were transferred to Aboriginal ownership under these processes – but this was the exception.</p>
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Read more:
<a href="https://theconversation.com/5-ways-the-government-can-clean-up-the-murray-darling-basin-plan-116265">5 ways the government can clean up the Murray-Darling Basin Plan</a>
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<p>Land restitution processes intentionally restricted what land Aboriginal people could claim. They were biased against properties with agricultural potential and, therefore, very few of the properties that were returned to Aboriginal ownership came with water entitlements. </p>
<p>At this crucial juncture in land rights reform, federal and state governments entrenched the inequity of water rights distribution by increasing the security of the water rights of those who historically held entitlements. Governments have yet to pay serious attention to the claims of Aboriginal people who see <a href="https://www.agriculture.gov.au/sites/default/files/sitecollectiondocuments/water/72-northern-basin-aboriginal-nations.pdf">a clear connection</a> between the past and the present in the distribution of water entitlements.</p>
<p>The <a href="https://www.mdpi.com/2079-9276/7/1/16">native title framework</a> has not helped the situation either. Native title is the recognition that Indigenous peoples have rights to land and water according to their own laws and customs. </p>
<p>But it’s difficult for those making a native title claim to get substantial interests in land and waters. The Native Title Act 1993 defined native title to include rights to water for customary purposes and courts are yet to recognise a commercial right to water.</p>
<h2>The third wave</h2>
<p>We also identified a third wave of dispossession, now underway. From 2009 to 2018, the water rights held by Aboriginal people in the NSW portion of the Murray-Darling Basin shrunk by at least 17.2% (2.0 gigalitres of water per year). No new entitlements were acquired during this decade. </p>
<p>The decline is attributable to several factors, the most significant being forced permanent water (and land) sales arising from the liquidation of Aboriginal enterprises. </p>
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Read more:
<a href="https://theconversation.com/australias-inland-rivers-are-the-pulse-of-the-outback-by-2070-theyll-be-unrecognisable-136492">Australia’s inland rivers are the pulse of the outback. By 2070, they’ll be unrecognisable</a>
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<p>With water rights held by Aboriginal people vulnerable to further decline, the options for Aboriginal communities to enjoy the wide-ranging benefits of water access may further diminish.</p>
<p>We expect rates of Aboriginal water ownership to be even smaller in other parts of the Murray-Darling Basin (and in jurisdictions beyond the Basin). Research is underway to explore this.</p>
<h2>Australia urgently needs a fair national water policy</h2>
<p>The Productivity Commission is now <a href="https://www.pc.gov.au/inquiries/current/water-reform-2020#issues">reviewing</a> Australian water policy, and must urgently address the injustices faced by Aboriginal people. </p>
<p>In developing a just water policy, governments must <a href="https://theconversation.com/aboriginal-voices-are-missing-from-the-murray-darling-basin-crisis-110769">work with First Nations</a> towards the twin goals of redressing historical inequities in water access <em>and</em> stemming further loss of water rights. Treaty negotiations may offer another avenue for water reform.</p>
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Read more:
<a href="https://theconversation.com/while-towns-run-dry-cotton-extracts-5-sydney-harbours-worth-of-murray-darling-water-a-year-its-time-to-reset-the-balance-133342">While towns run dry, cotton extracts 5 Sydney Harbours' worth of Murray Darling water a year. It's time to reset the balance</a>
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<p>Over recent decades, Australia has been coming to terms with its colonial history of land management, returning more than a third of the continent to some form of Indigenous control under a “land titling revolution”.</p>
<p>But a water titling revolution that reconnects water law and policy to the social justice agenda of land restitution is long overdue. Indigenous peoples must have the opportunity to care for their land and waters holistically, and share more equitably in the benefits of water use.</p><img src="https://counter.theconversation.com/content/141743/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lana Hartwig has served as a consultant to Murray Lower Darling Rivers Indigenous Nations (MLDRIN) and the Murray-Darling Basin Authority (MDBA). </span></em></p><p class="fine-print"><em><span>Sue Jackson receives funding from the Australian Research Council. She is a member of the Murray Darling Basin Authority's Advisory Committee on Social, Economic and Environmental Sciences. </span></em></p><p class="fine-print"><em><span>Natalie Osborne does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Across the NSW portion of the Murray-Darling Basin, Aboriginal people make up almost 10% of the population. Yet they hold a mere 0.2% of all available surface water.Lana D. Hartwig, Research Fellow, Australian Rivers Institute, Griffith UniversityNatalie Osborne, Lecturer, School of Environment and Science, Griffith UniversitySue Jackson, Professor, ARC Future Fellow, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.