DOC is appealing a Northland Regional Council decision to permit 17 avocado orchards to draw water from the Aupouri aquifer which they say is the source of water for the Kaimaumau Wetland.

This story was originally published on Newsroom.co.nz and is republished with permission.

A battle over the rights of a wetland and 17 avocado orchards to ground water will unfold in the Environment Court this week.

The Department of Conservation (DOC) is appealing a resource consent granted by the Northland Regional Council allowing 17 avocado growers to take over two million cubic metres of water a year from the Aupouri aquifer.

KEVIN MATTHEWS Orchids found in the Kaimaumau Wetland which DOC believes draws water from the Aupouri aquifier which avocado orchardists have been permitted to draw water from.

The growers are planting over 600 hectares of avocados, and the consent secures their right to water for 15 years.

DOC believes the aquifer may supply the Kaimaumau Wetland, and says any drying of the wetland could lead to "irreversible loss" of habitats for threatened species. It also believes proposed mitigation involving monitoring levels of water would be largely ineffective as there was no baseline data to begin with.

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BAYLEY MOOR/STUFF Avocados are botanically a large berry which grow on trees.

The Northland Regional Council's consent decision says risks to the wetland can be averted through "adaptive management conditions" and disagree with DOC's belief that baseline monitoring is needed before consent to take water is granted.

The council's decision document acknowledges the potential vulnerability of the aquifer "due to its connection to the sea and the variable amounts of rainfall recharge related to climatic changes and the clearing and planting of forestry blocks".

"Lowering of groundwater levels due to more abstraction poses a risk of sea water intrusion and a risk to the ability of existing users to abstract groundwater and on the health of the Kaimaumau Wetland."

The council's decision concluded the aquifer could cope with the amount of water the applicants requested and their requests were granted. Conditions were specified including a gradual increase in permitted water take over a period of years in order to monitor the effect on the aquifer.

The 1860-hectare Kaimaumau Wetland is one of the largest freshwater wetlands remaining in New Zealand and is home to endangered and at-risk flora and fauna including fernbirds, mudfish and native orchids. Northland has lost 94.5 percent of its wetlands and freshwater wetlands cover just 1 percent of New Zealand's land mass.

In a submission during the initial consent process on behalf of DOC, a wetland ecologist said not enough was known about the aquifer. The assumption a continuous "iron pan" layer separates the deep water the orchardists plan to take from water forming part of the wetlands was incorrect.

"Information on whether wetland is connected to groundwater is based on anecdotal accounts and observations and there is no detailed analysis of the hydrology and ecological function of the whole wetland."

The submission noted information gathered by DOC indicates that the assumptions used by the council "are not correct".

Any drop in water levels could mean a drying out of the wetlands which would allow weeds such as Sydney golden wattle to establish. The wattle is already a pest plant in the wetland.

Local native orchid enthusiast Kevin Matthews describes the wattle as forming a monoculture once established.

"It [the wattle] is basically impenetrable. It needs dry ground to start off on, but it will grow in wet conditions."

Very little flourishes underneath the wattle, including the native orchids Matthews photographs.

"Because of the general destruction of wetlands over time, their habitat is becoming more and more reduced."

The orchardists' application to take the water states the irrigation will provide a socio-economic effect for one of New Zealand's poorest regions.

"The avocado orchard development will result in a tangible impact on the local community, which can only fully materialise with the irrigation water being sought under this application. This includes the creation of full-time jobs in addition to continuation of seasonal jobs."

If 670 hectares of avocado orchards are established, the applicants anticipate the equivalent of 70 seasonal jobs would be created and $2m would be spent in the region on the orchards.

The value of the avocado industry recorded an all-time high of $200m in 2016/2017. Exports accounted for much of the recent growth. Australia is the main recipient of New Zealand's avocados, but Asian countries are a growing market with South Korea, Singapore, Thailand and more recently, China, buying the fruit.

The goal to raise the value of the industry to $275m would place avocados in New Zealand's top five horticultural exports.

The industry is currently going through what's described as a gold rush, with dairy farms being converted to orchards in the north of New Zealand and a focus on increasing the production from trees.

Part of the key to unlock the value of the industry though comes down to water. Avocados have a shallow root system which means the trees don't seek water with deep roots. In dry areas irrigation is required to get a decent crop.

The application from the orchardists gathered 57 submissions when it was made. It was a limited notification application, meaning only those directly affected as a property owner or occupier in the region were allowed to submit. Of the approximately 1000 people notified, 42 opposed the application, eight supported it and seven submissions were neutral.

Community concerns raised at the hearing by submitters included the potential of the water table dropping and affecting people with shallow bores as well as the risk of salt water entering the aquifer.

Others described the application as speculative and "excessive and greedy" and with the potential to lower the value of properties who may miss out on water allocations as a result.

Also questioned in statements was who was monitoring whether irrigation was taking place before consent had been granted: "Why have these landowners not been prosecuted? As far as we are concerned no consent/no water."

This referred to five growers who decided to plant trees before the consent was granted. It was later found they were using as much as 10 times the amount of water they were legally entitled to.

The growers were invited by the council to apply for an interim consent. Three of the five growers applied for and received interim consent. Two were given abatement notices.

Karyn Nikora-Kerr, who is part of advocacy group We Are Water, said most people in Northland have concerns about water.

"When you plant trees at this time of the year, you're going to have to water them. If you haven't got consent, then how do you do it? You get temporary consent. That's wrong from my eyes.

"I'm not prepared to risk water for somebody else's gain. Our whole community, every community, is reliant on water."

Nikora-Kerr is organising people to attend this week's hearing.

"I feel like the aquifer doesn't have a voice. I'm part of that voice."

The appeal will be heard by Judge Jeff Smith at an Environment Court hearing at Comfort Hotel Flames in Whangarei.

This story was originally published on Newsroom.co.nz and is republished with permission.