Irrigators in southern NSW say unmetered and unlicensed flood plain harvesting in the north has denied the state more than a fifth of its annual general security allocation.
The claims were made in a submission to a NSW Upper House inquiry by Southern Riverina Irrigators.
SRI said the implementation of a regulatory change to flood plain harvesting, authorised by the Water Minister, Melinda Pavey, in February, had denied other irrigators general security water.
The inquiry, headed by Mick Veitch, is looking at exemptions from certain licence and works approvals, granted under the Water Management Act 2000.
When granted, the exemption allows water to be harvested from a floodplain, and for associated water management work to be undertaken, provided certain conditions are met.
'The recent use of this regulation has caused confusion. Clear communication is required around its application,: Mr Veitch said,
"There needs to be transparency around the decision to create and implement this regulation.
"The Regulation Committee will examine how and why this regulation came into existence, and how it has been applied by the Minister."
Floodplain harvesting is the capture and use of water flowing across a floodplain.
It's regarded as an essential source of irrigation water for industry, particularly in the Northern Murray-Darling Basin areas of NSW.
But SRI chair Chris Brooks and vice-chair Darcy Hare said they'd uncovered considerable discrepancies in volumes of water removed from the northern system, after the February rainfall event, and Ms Pavey's sudden implementation of an exemption.
In its submission to the inquiry, SRI said the regulation exempted people from the licencing and approvals regime of the Water Management Act, "effectively giving people the right to take FPH water without meters, costs, supervision or express approval from NSW since 7 February 2020.
"There is a small amount of rainfall-runoff that can be legally withheld/harvested without a licence by a basic landholder right for collecting some rainfall-runoff - this amount is 10 per cent of the total estimated rainfall-runoff for the valley.
"To put that in context, that is a number significantly smaller than 10pc of the rainfall in a valley. In most cases, annual rainfall runoff for a valley is 2pc to 4pc of the total rainfall - which would be 100ML to 200ML for a 1,000 hectare property."
SRI vice-chair Darcy Hare said they've uncovered considerable discrepancies in volumes of water removed from the northern system after the February rainfall event and Ms Pavey's sudden implementation of an exemption.
He, and chair Chris Brooks, said the exemption allowed irrigators from Gwydir, Upper and Lower Namoi, NSW Border Rivers to take around 20,000Ml of 'passive take' water, after flood plain harvesting access was granted.
According to the NSW government, passive take is any water remaining in supply channels and surge areas after overland flow has ceased.
The NSW Department of Primary Industry and Environment (DPIE) had increased the passive take figure to 30,000 megalitres,
But, evidence given under oath by SRI, had the number sitting around a massive 900,000Ml.
"To put this figure into context, according to historical Murray-Darling Basin Commission and Murray-Darling Basin Authority data, this would have equated to a long term average of 720,000Ml at the SA border and resulted in a 21.5 per cent general security allocation for NSW irrigators," Mr Hare said.
SRI also received confirmation from the DPIE there had not been one single flood plain harvesting license issued in NSW.
The SRI submission also argued there were currently no flood plain harvesting licences or approvals for water supply works under the Water Management Act in NSW, so no-one was licenced to take water in that way.
While there were approvals for flood works, under the 1912 Water Act, it was unclear how many were valid, as they generally lapsed after ten years.
Mr Hare said when he turned on his pumps, on the Murray River, the authorities knew exactly what he was taking.
"I don't care what you grow, but if you are going to take water in an unsustainable area, which has economic and social impacts, then I have a problem," he said.
"Effectively these irrigators have no license, are unmetered and holding vast amounts of water in storages and to add insult, in some cases in storages built without the required work orders as per requirements of the basin plan and yet here in the southern basin we are metered and compliant."
He said it was not an issue of north versus south, for irrigators, instead that the rules were not being applied fairly
"There can't be two sets of rules, one for the north and one for the south," Mr Hare said.
Flood plain harvesting had a serious impact on water allocation in the south and contributed significantly to widespread economic and environmental damage.
"Billions of dollars in productivity has been lost in the south, productivity which could have been shared across thousands of irrigators and their communities.
"Yet the NSW government continues to turn a blind eye and we demand an equal playing field."
Ms Pavey has been contacted, for comment.
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