Freshwater campaigners say the independent review of farm modelling tool, 'Overseer', released today has found profound weaknesses with the tool and in doing so has proved the strength of Government and regional councils turning to greater control of inputs such as fertiliser, irrigation and cow numbers.

Councils and the agricultural sector have used the farm modelling tool, Overseer, for a number of years to assess losses of pollution to waterways from individual farms. An expert panel, commissioned by the government, concluded that “in its current form, it would not have confidence in Overseer’s estimates of nitrogen lost from farms.”

Because of the model’s weaknesses, freshwater campaign group Choose Clean Water says the review highlights the strength and value of government and regional councils turning to controlling agricultural inputs.

Choose Clean Water says the best thing to come from the review is that the Government will look into the “greater use of controls on practices and inputs to manage nitrogen loss.”

“We know which types of land-use and practices are associated with higher losses of nitrogen. Fertiliser application, imported feeds, irrigation and high stocking rates – all components of high intensity farm systems – increase the risk and loss of nitrogen pollution to waterways alongside any further conversion of land to more intensive uses.”

“The Government has already introduced a control on fertiliser application, capping the use of synthetic nitrogen fertiliser at 190kg/ha/yr. While this is welcome and should be commended, it is only a first small step in recognising the value of input controls in the work to save the health of our rivers and meet our climate change responsibilities.”

“The Government has made some attempt to control further intensification through freshwater reform but these have been poorly enforced and monitored by councils and the Ministry for the Environment.”

Poorly considered irrigation projects are still on the cards for some councils who have failed to learn the lessons of Ruataniwha and Waimea dam projects; that irrigation drives intensification that isn’t compatible with a healthy river and that, when it’s attempted, large-scale water storage schemes for irrigation end up costing far more than councils expect and the public has to bear the cost.

It is vital now, in light of the review, that the Government clearly directs local councils to recognise the value of and implement wider use of input control in their planning to protect the health of their communities’ freshwater.

The Government itself can act more swiftly on improving input control regulations by tightening fertiliser caps and putting a moratorium on any further irrigation until regional plans are in place and consents can be reassessed.

The Government and regional councils must ignore protestation from agricultural lobby groups around input controls and the repetition of the unqualified claims of that ‘innovation’ requires a free for all on inputs.

‘Our rivers and lakes are still getting sicker and will worsen with the effects of climate change if degradation continues. Meanwhile, some loud voices in the agricultural sector lobby are still protecting their highest polluters by pushing central and regional government for weakened rules.”

“Leading farmers, who have already reduced their inputs, continued to be let down by their agricultural sector organisations.”

The group says the Government must be stronger and clearer on what healthier land-use in Aotearoa New Zealand will look like and how environmental reforms contribute to a healthier future for all New Zealanders.

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