Politics not water the driver of new Murray Darling-Basin Plan

In the decade since it was established, the Murray-Darling Basin Plan has slowly shifted from a way to balance the needs of industry and the environment to a politically convenient weapon.

The federal government announced a new basin agreement with the states (except Victoria), that will extend the plan's timeline and provide money for water saving projects, while opening up the option of more buybacks and compensation for communities affected by the increased water recovery.

The proposal to open up buybacks was condemned across much of the basin, but was well received in South Australia, a key player in basin politics. The day after announcing the policy, Water Minister Tanya Plibersek was in Adelaide to spruik it.

A quick history lesson; when the basin plan was negotiated and designed in 2012, South Australia continued to hold out. It felt the other states sucked up all the water before it got to South Australia, leaving its environment in ruins.

SA wanted more and an 450-gigalitre allowance for the environment was tacked on to the plan to get it over the line.

Unlike much of the modelling within the basin plan, this 450GL figure is purely arbitrary. It was plucked out to satisfy political requirements and does not hold the same legislative consequences (in the form of forced buybacks), which is why over the last decade no effort was made to recover the water.

South Australia still feels the same sense of environmental injustice that drove it to resist signing the initial plan, particularly within Adelaide, where Prime Minister Anthony Albanese promised the basin plan would be delivered in full during the 2022 election.

More than any other part of the basin South Australia is reliant on the actions in other parts of the catchment and Adelaide is the largest population centre in the country using MDB water.

Two of Adelaide's marginal seats are a major interest to Labor's future ambitions - Boothby and Sturt, stretched across the city's affluent southern and eastern suburbs.

In 2022, Labor won Boothby from the Liberals for the first time in more than 70 years. But the Liberal still received more first-preference votes and Labor was forced to rely on preferences going their way.

Labor wants to sandbag Boobthy and flip the adjacent seat of Sturt, which the Liberals hold by less than half-a-percent.

But how can Labor push ahead with a policy as unpopular as water buybacks for the sake of a few seats? Of the more than a dozen seats that exist in the Murray Darling Basin, Labor holds four, none of which can be considered heartland agricultural seats.

Two of those are the metropolitan ACT seats, followed by another urban seat in Bendigo in Victoria, which is dominated by its city namesake with a strong mining and industrial focus along with geographically-diverse bellwether seat of Eden-Monaro, which only includes a portion of the Basin catchment in the seat, running from the NSW south coast up onto the Monaro, that runs livestock rather than irrigated agriculture.

Although these areas are geographically part of the basin, none of their industries rely on their rivers and voters would see no change in their quality of life if more water was removed from their community.

The rest of the Murray-Darling Basin is controlled by a mix of Liberals, Nationals and independents, all of which are safe seats for the incumbents.

By pursuing water buybacks, Labor stands to lose little and gain much in urban Sydney, Melbourne and Brisbane seats, where the party is fighting off the Greens.

The new policy services a defensive strategy in inner-city seats, where the environment is consistently ranked as a top three issue in inner-city seats.

The basin debate has been simplified to "more water is better for the environment". Pursuing the 450GL of environmental water helps Labor to stem the leak of left-leaning voters to the Greens.

The recent announcement puts pressure on the Greens to support the upcoming legislation - after all, it's designed to deliver what the Greens want; more water for the environment.

If the Greens act as a roadblock, it allows Labor to double down on the narrative the Greens let perfect get in the way of good - which is currently playing out in the housing debate - that continues to hang over the party from the Gillard years, when it refused to support the carbon tax because it didn't meet the party's high standards.

Labor's new basin agreement will also force the Liberal Party to show its environmental credentials as it attempts to regain inner-city seats lost to independents, while the SA Liberal senators are well aware of how important delivering the plans is to winning the hearts and minds of their voters.

The announcement could create a schism in the Coalition, with inner-city Liberals worried about getting re-elected facing off against the Nationals and rural Liberals such as Sussan Ley, who vehemently oppose any attempt to remove more water from their communities.

For now, the Coalition is singing from the same hymn sheet - in favour of the extended timelines, but against reckless buybacks - but the holding pattern is yet to be pressure tested and eventually sides will be picked.

Ms Plibersek is already using the policy to pressure Labor's rivals on both sides of politics.

"This is really a very important question for the Liberals and Nationals; do they support South Australia or don't they?" she said.

"And will the Greens support water for South Australia, for the whole of the Murray-Darling Basin?"