Understanding risks of hypoxic blackwater and low dissolved oxygen events under climate change

This report documents the state of knowledge of the secondary, or indirect, impacts of climate change and prioritises topics for investigation in the MD-WERP climate adaption theme.

Science and research

MD-WERP theme	Climate adaptation
MD-WERP theme 1 project	Climate adaptation foundational science
Research lead	CSIRO
Authors	David Robertson and Andrew Freebairn
Author contact details	David Robertson
Date of publication	December 2024
Report full title	Understanding risks of hypoxic blackwater and low dissolved oxygen events under climate change
Keywords	hypoxic blackwater; low dissolved oxygen; climate change; Murray–Darling Basin; streamflow; simulations; floodplain; inundation; organic matter accumulation; hydrological; water quality; management interventions
Summary of output	Climate change projections indicate that the Murray–Darling Basin will become warmer, and rainfall is likely to decline. The impacts on the hydrological regime of climate change will include lower mean annual runoff, fewer high flow days and longer periods of low flow. The hydrological regime influences water quality in the Basin and therefore climate change is expected to impact water quality outcomes. This report describes a study investigating the consequences of climate change for the hydrological conditions that lead to hypoxic blackwater and low dissolved oxygen events at more than 150 stream gauges from across the Murray–Darling Basin.
Key findings / recommendations	Under future climates, the risk of water quality events related to hypoxic blackwater, and low dissolved oxygen levels is likely to be higher. Management interventions can mitigate these risks to some extent, both locally and at a river system scale. Water management plans should adapt to consider climate change and reflect impacts on water quality as well as water quantity.
Target audience	Water managers, researchers, Australian Government, state governments, local governments, community, water and environmental consultants

Report
Publication title	Published	File type	File size
Understanding risks of hypoxic blackwater and low dissolved oxygen events under climate change	03 Mar 2025	PDF	2.41 MB

Published date: 19 May 2025