What the Menindee fish die-off means for irrigators

A third mass fish kill, less than a month after a million fish died in the Menindee Lakes area, has added a new dimension to the drought gripping Eastern Australia over the last 18 months. With many questions still yet to be answered about the role of the Murray-Darling Basin Authority (MDBA) and the NSW Government allowing this environmental catastrophe to unfold, irrigators across NSW, Victoria and South Australia are being forced to revaluate the security and surety of their water allotments and farming practices.

Record low levels of water in the Menindee Lakes set the stage for a disaster like this, with water levels reaching that of the millennium drought. This comes just a year after the Lake system was near capacity at over 1500 GL in 2015. A critical lack of inflows into the lakes resulted in largely stagnant water pooling, which allowed for an algal bloom to take off within the system. A sudden 20-degree drop in temperature after a brutal heatwave then resulted in the mass killing of the algae, which in turn led to a bacterial bloom feeding off the dead algae, sharply reducing the oxygen levels of the water, resulting in the kill-off.

While this seems like an unpredictable series of events, and no doubt MDBA and WaterNSW would have striven to stop such an event if they were aware of the threat they posed to the Murray-Darling ecosystem, it highlights the considerable threats rural Australian communities and businesses face in the decades to come.

While irrigation in Australia has always required an acute awareness of water availability, Australian farmers are facing some of their hottest and driest years on record, according to figures published by the Bureau of Meteorology earlier this month. These extremes of weather conditions are set to only increase. Political pressure to allocate more water to the environment, combined with greater uncertainty about rainfall forecasts and drier climate trends will cause water authorities to become more conservative in how and when they allocate water.

This uncertainty was a strong theme in recent conversations with farmers. Of the 60 irrigators we spoke with late last year, over 60% said they were concerned about the lack of financial tools to manage the impact of poor weather on their operations, particularly the risk that their water allocation is cut. This is especially acute for irrigators who have made large investments, whether in land, new plantings or technology, and have a large debt burden to repay. It’s clear that irrigators are in dire need of new risk management tools—such as weather-index products—to combat what may become the new normal of adverse weather conditions.

Photo by Rob Greggory, Chairman of the Menindee Tourism Association