The lower Murray is officially on life support. Will we save it?

At 2,500 km long, the Murray is Australia’s longest river. It provides 3 million people with drinking water and irrigates around 1.5 million hectares of farmland.

But this intensive use has come at a cost: the lower Murray — defined as the River Murray downstream of the Darling River and its meandering creeks and floodplains — is now dangerously environmentally degraded.

In mid January, the lower Murray was listed as a critically endangered ecological community under Australia’s nature laws. This means there’s an extremely high chance its native ecosystems will become extinct within the immediate future, in as little as ten years. The Macquarie Marshes in northern New South Wales, one of the largest inland wetlands in south east Australia, was listed as endangered on the same day.

The health of the lower Murray matters greatly. It is the lifeblood for a large swathe of southern Australia and supports a diverse range of unique plants and animals, local economies and the well-being of people that love and rely on it.

Connecting the basin to the sea

The lower Murray is one of a growing number of Australian ecological communities at risk of becoming extinct. These communities include all the plants and animals co-existing in an area, in some cases for millions of years.

The lower Murray winds through expansive floodplains, limestone gorges and swamplands as it flows 830 kilometres downstream from its junction with the Darling River to the sea near Goolwa.

The internationally recognised lower reaches of the river, including Lakes Alexandrina and Albert and the Murray Estuary, connect the vast Murray-Darling Basin with the ocean. This includes the famous Coorong, the setting of the book Storm Boy which captured the hearts of Australians and showed us the glory of a rich wetland landscape full of abundant fish and birdlife.

Less water, less life

The lower Murray supports a wealth of native Australian fauna. But the development of weirs and barrages since the twentieth century to regulate the water level and divert water for irrigation have dramatically altered the flow of the river.

This regulation has supported increased European settlement, trade, and agriculture along the river, setting the scene for the region as we know it today.

Nowadays, inflow to the Lower Lakes is about half of what it once was prior to European settlement. In those days, the river experienced flows the plants and animals needed, which connected floodplains to the river and flushed the whole Murray-Darling Basin.

However, river regulation has drastically altered the water flow and ecology of the lower Murray. The destruction of native vegetation, poor water quality and invasive species such as foxes and carp have also taken their toll.

It is increasingly clear the lower Murray region is changing at a rapid rate, to a drier and warmer climate with less flow and more extreme droughts.

To a casual observer, these lower stretches of the Murray appear to be doing okay. The river typically has water, thanks in part to how it is managed, and it still experiences big replenishing floods.

You can still catch an iconic Murray cod (pondi in Ngarrindjeri language), and the pelican (ngori in Ngarrindjeri) still effortlessly roams the Coorong. But look more closely and the danger signs are clear.