Lower Lakes independent science review confirms river managers are on right track

The Murray⁠-Darling Basin Authority has welcomed a report from an independent panel which confirms water management of the Lower Lakes in South Australia is informed by evidence-based science.

MDBA Chief Executive Phillip Glyde said the findings show that river managers are on the right track in managing this integral part of the Murray-Darling Basin.

“The way the Lower Lakes are managed had in the past been contested, with some communities questioning whether the lakes were fresh prior to construction of the barrages and whether removing the barrages would result in an increase in water available for consumptive use,” Mr Glyde said. “This comprehensive review of the science confirms it’s time to put history to bed and focus on the future.”

The findings are consistent with the understanding of the system that underpinned the MDBA’s assessment of the environmental needs of the Coorong, Lower Lakes and Murray Mouth (CLLMM) region that informed the Basin Plan.

“The additional flows secured under the Basin Plan are enhancing the ecological outcomes, building resilience in the system and securing inflow during dry years.”

The CLLMM region is a key section of the Murray-Darling Basin and an important environmental, social and economic national asset. The region has significant importance for the Ngarrindjeri people. The Lower Lakes are a significant part of the internationally recognised Coorong and Lakes Alexandrina and Albert Ramsar listed wetland.

In late 2019, it was agreed to review the science and clarify the appropriate approach to river management for the region.

The independent review – recommended by the Murray⁠-Darling Basin Authority’s Advisory Committee on Social, Economic and Environmental Sciences (ACSEES) – examined hundreds of scientific studies on the Coorong, Lower Lakes and Murray Mouth and their report was peer-reviewed by close to 100 technical experts.

Chair of ACSEES, Professor Rob Vertessy said the comprehensive review profiled the significant base of scientific knowledge underpinning the management of this important section of the Murray⁠-Darling Basin.

“After examining a significant canon of research and consulting with almost 100 technical experts, the independent panel concluded that there are sound scientific reasons for why the Lower Lakes are managed as they are,” Professor Vertessy said.

Mr Glyde said the MDBA supports the panel’s findings that the lower lakes were largely fresh prior to European settlement, and that maintaining the freshwater status of the Lower Lakes is needed to protect the social, economic and environmental values of the region.

“It is clear from the report that removing the barrages would contravene obligations under the Ramsar convention and put at risk threatened species,” Mr Glyde said.

“The report also notes the socio-economic impacts that would be caused if the barrages were removed, and this is obviously not something we support.”

Findings relating to the fresh water history of the Lower Lakes were informed by palaeoecological records, water balance estimates, hydrological and hydrodynamic modelling, and traditional knowledge of the Ngarrindjeri people and anecdotal evidence of early explorers and colonists.

Mr Glyde said he understands some Basin communities will be disappointed that the review hasn’t unearthed any new or spare water.

“There has been immense community interest in the history of the lakes, which is why we wanted this science review to be completed – to provide additional assurances to Basin communities.

“While the report confirms our previous understanding of the history of the lakes, it actually highlights the big challenge for all governments – and that is sharing this vital resource in the face of climate change.

“We will use the results of the review to further support our current work in the area of climate change adaptation.

“This evidence will help governments make informed decisions and plan for the future.

“We’d like to thank the independent panel for undertaking this important review, and ACSEES for managing it in a professional and timely manner,” Mr Glyde said.

The report Independent Review of Lower Lakes Science Informing Water Management has been delivered to the Murray⁠-Darling Basin Authority for continued reference in current and future water management.

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