The mass death of fish in Menindee Lakes is a disaster that has been a long time in the making. The story goes back to another disaster on the Darling River, a massive outbreak of blue-green algae that poisoned hundreds of kilometres of the river in 1991 and 1992. The outbreak was a dramatic illustration of decades of warnings from scientists and economists that too much water was being extracted from the river.

The first response was the imposition, in 1995 of a cap on extractions. The cap was meant as an emergency measure to prevent further disasters while a long-term policy was worked out. Nearly 25 years later, it is still in effect. The cap is supposed to be replaced later this year by a system of sustainable diversion limits, worked out on the basis of scientific evidence. But a litany of disastrous policy failures, of which the fish kill is among the more dramatic outcomes, cast doubt on whether this schedule can be met.

The sustainable diversion limits were worked out in a massive scientific and economic exercise as part of the Murray-Darling Basin plan, launched by the Howard government in 2007.

Unfortunately, the bureaucrats in charge of the plan mishandled the politics, failing to rule out compulsory cutbacks in irrigators’ water rights, even though it was obvious that the only feasible option was to buy rights back from willing sellers, who were, and are, plentiful. This opened space for a scare campaign from industry lobby groups, with rowdy meetings at which the draft plan for the basin was publicly burned.

Despite these missteps, the Rudd-Gillard government managed to achieve agreement on a compromise plan that was acceptable to irrigator groups, while securing significant flows of water for the environment and for downstream water users, particularly in South Australia. The cost-effective part of the scheme, buybacks from willing sellers, remained in place, while irrigators were mollified by massive assistance for projects aimed at enhancing the efficiency of on-farm water use. Legislation implementing the deal was passed with bipartisan support.

All of that changed after the 2013 election. Within its first 100 days, the Abbott government reversed the Labor government’s declaration of threatened ecological communities in the Murray-Darling Basin as endangered under the Environment Protection and Biodiversity Conservation Act. In terms redolent of the culture wars to come, science-based environmental policy was described as green tape.

Worse was to come with the appointment of Barnaby Joyce as the minister for water, a position held in the previous LNP government by Malcolm Turnbull. A multitude of actions Joyce took as minister, from blocking water buybacks to cutting the allocation of water to the environment were so damaging as to seem deliberately designed to destroy the fragile ecosystems of the Murray-Darling Basin, and to produce outcomes like those we see today. His successor, David Littleproud, has been no better.

Joyce’s policies were reinforced by the NSW Primary Industry department, also run by National party ministers. As has been shown in a series of shocking reports on large-scale water theft, the department has been either acquiescent or complicit in undermining the basin plan. Many of the worst cases have involved large-scale cotton producers. It is, however, a mistake to focus on particular crops and industries when the problem is one of systemic mismanagement.

An equally serious development is the politicisation of the Murray Darling Basin Authority, established to manage the basin plan, but now little more than an advocate for the destructive policy agenda of the LNP. As well as supporting cuts in environmental allocations, the MDBA permitted systematic mismanagement by the New South Wales government.. In February, the MDBA rejected a declaration by leading scientists and economists expressing concern that funds allocated to infrastructure projects were being wasted while failing to meet our international obligations to preserve wetlands.

For centuries the rivers sustained Aboriginal culture. Now they are dry, elders despair Read more

In part, this is the usual story of powerful financial interests triumphing over the public good. Irrigation lobbyists benefit from a larger irrigation sector, whether or not individual irrigators are doing well. And some large irrigators have benefited greatly from cheap water and publicly subsidised infrastructure investment.

The crucial factor, however, is the continuous culture war in which Joyce and Littleproud are on the frontline, along with the majority of LNP MPs and virtually all of the rightwing intelligentsia. Among the perceived enemies of the culture warriors are environmentalists and scientists, correctly seen as largely overlapping groups. So, in rejecting scientific evidence as a basis for water policy, Barnaby Joyce made it clear that his primary concern was to “make sure we don’t have the greenies running the show”.

The central front in this culture war is climate change. Joyce is an overt sceptic, while Littleproud is on record as stating that he “doesn’t ‘give a rats’ whether climate change is man-made” .

Events like the Menindee fish kill bring home the cost of treating the environment as a cultural battleground. The culture warriors’ policy amounts to listening to what scientists say we need to do, then doing the opposite. This is a guaranteed route to global disaster.