Bay of Plenty fruit and vegetable growers don’t want to be left high and dry in a review of water use by the regional council.

The Tauranga Geothermal System Management Plan will become part of a wider strategy being developed by Bay of Plenty Regional Council through draft regional plan changes relating to geothermal water, which is water 30°C and over.

Regional council strategy and science general manager Namouta Poutasi says the draft plan proposes “no direct effects” on existing geothermal or freshwater consents in the Tauranga geothermal system.

“The draft plan change will continue to provide a sustainable and reliable heat and water source, which would be beneficial for growers who rely on these sources.”

New Zealand Kiwifruit Growers Inc (NZKGI) CEO Colin Bond says a relatively small number of kiwifruit orchards in the Bay of Plenty use water from the Tauranga geothermal system for irrigation and frost protection.

Feedback collection

Speaking to Coast & Country News prior to public submissions closing on January 31, Bond says as the advocate for New Zealand’s kiwifruit growers, NZKGI was collecting feedback from industry stakeholders on the management approach for geothermal water which will be submitted to the council.

“NZKGI has a keen interest in this topic as the use of water is essential not only for growers’ production of kiwifruit, but also for the important economic benefits that our industry contributes to the Bay of Plenty,” says Bond.

New Zealand Kiwifruit Growers Inc (NZKGI) CEO Colin Bond.

During the submission period, NZ Avocado also encouraged feedback from its Bay of Plenty growers.

CEO Brad Siebert says growers use their bore water for several uses across their orcharding operation from irrigation and frost protection to sprays.

The industry also works closely with NZKGI, while he says NZ Avocado would be supporting a submission by HortNZ to the regional council on its draft Tauranga Geothermal System Management Plan “unless there are differing views or additional topics raised by our growers”.

“In general, NZ Avocado supports more work on understanding our growing region’s water resources towards an equitable opportunity for growers to access the water they have available on their land with minimal compliance requirements,” says Brad.

New Consents

Namouta says the provisions of the draft Tauranga Geothermal System Management Plan and the draft geothermal plan change propose a more streamlined and simplified application process for new consents.

“It’s important to note that, due to the way the Tauranga geothermal system works, the water temperature within a bore can diminish over time.

“We try to avoid this through conditions of consent and monitoring.”

Resource consents for water takes under 30°C fall under the freshwater rules.

Bay of Plenty Regional Council strategy and science general manager Namouta Poutasi.

“This would then come with different requirements for consent and ongoing compliance,” she says.

Namouta says there will be further opportunity through the formal plan change process for more feedback to be gathered.

There are 172 consented geothermal takes in the Tauranga geothermal system, 73 for irrigation and/or frost protection and 98 are for pool and/or space heating.

Namouta says current levels of use are considered “sustainable system-wide” and should not induce excessive levels of cooling.

Geothermal water use

About 9.5 million m3 per year of geothermal water is consented for extraction from the Tauranga geothermal system.

Those takes are both for ‘geothermal use’ and for ‘non-geothermal use’.

Namouta says most of the consents are for relatively small volumes, with about 25 per cent of the geothermal water used for ‘non geothermal’ uses such as irrigation and/or frost protection for commercial horticultural crops.

Tauranga is a low temperature (between 30°C and 70°C) geothermal system, which is “the warm parts” of the groundwater resource.

“This means the use of one resource affects the other and, therefore, the two resources must be managed in an integrated way,” says Namouta.

The Tauranga geothermal system extends more than 60kms from Katikati-WaihĪ Beach in the north-west to Te Puke-Maketu in the east, with the dominant heat source appearing to lie near Tauranga.

Namouta says although it is less well-known than the hot geothermal systems of the Bay of Plenty region, such as Rotorua, it is used and valued in many ways.

“A system management plan is being developed to ensure this system is managed in an integrated and sustainable way, while balancing the values of the community.”