The recent tragedy of fish deaths below Menindee Lakes is a terrible outcome of what looks like a perfect storm of events.

There can be no doubt the lack of water in the system above Menindee is a significant contributor.

The Bureau of Meteorology (BOM) reports that over the past 21 months several areas in the northern basin have received rainfall to the tune of the lowest on record.

The BOM's annual climate statement lists 2018 as Australia's third warmest on record, and for NSW the sixth driest on record.

Irrigators receive water allocations that relate to water inflows into storages. The allocations above Menindee have been zero for about 18 months.

Environmental water is treated exactly the same; if there are not sufficient inflows then there is no allocation. There has simply been no water, therefore no allocation, and rivers run dry, reflecting a natural cycle.

The preliminary observation by experts (and an apparent emerging consensus) is that a cold snap killed the algal blooms, which deoxygenated the water.

These factors have all contributed to the event.

The hotter the day the more water is lost to evaporation, and it's been hot. ( Supplied: Bureau of Meteorology )

Cotton and rice suffering too

There are very few solutions being offered up. One thing is for sure — the blame game is not helpful.

The assertion that the lakes could have been better managed reflects the difficult balance water managers are required to address when considering multiple priorities.

Loading

The truth is increasingly becoming a casualty in this tragedy as more and more people use the circumstances as a lever to run their own agendas with escalating shrillness.

Singling out particular commodities is not constructive either.

Both cotton and rice have experienced very low plantings due to lack of water allocation. When they have allocations, these commodities are among the most water-use efficient in the world.

Australia's cotton industry is considered among the most water-efficient in the world, with water-use efficiency improved by 40 per cent over a 10-year period.

The Australian rice industry (which by the way does not occupy the northern basin) is an exemplar of water utilisation, with a 60 per cent increase in water-use efficiency over a decade.

Farmers exercise their option to grow the crop that best suits their preferred management regime, it could be perennial horticulture (oranges, almonds and grapes), annual cereal crops or high-quality pastures that are the best option for an irrigator. Once an allocation is acquired it is the farmer's choice what it is used for.

Allocations made for fish breeding, too

Storing water for future use is difficult.

Sorry, this video has expired Viral video of mass fish kill

Aside from the aforementioned multiple priorities for water, it also evaporates, and in Menindee it proportionally evaporates much faster due to the shallowness of the lakes. And the hotter the day the more water is lost to evaporation.

While the tragic impact on fish will have a socio-economic impact around Menindee, it must also be recognised irrigation industries underpin the economies of many regional communities.

The implementation of the Basin Plan is already having a negative impact on many towns due to the transfer of water to the environment.

It must be noted that late last year, environmental water allocations were made to support fish breeding and habitat improvement in the Lower Darling River.

These are very difficult times, seriously exacerbated by the drought. Those looking for a scapegoat achieve nothing more than fuelling media coverage and unrest. It does little to better understand and recommend future solutions, nor sadly does it bring the fish back.

Les Gordon is the chair of the National Farmers' Federation water taskforce.