Horticulture under threat on the Heretaunga Plains
A far reaching Water Conservation Order has been applied for the Ngaruroro River in Hawke’s Bay which could have potentially devastating affects for horticulture on the Heretaunga Plains.
The Order (WCO) proposes completely unworkable restrictions of a total volume of allocated water of 1581 litres/second for the lower Ngaruroro River catchment, and Clive River, when the river is less than three times the naturalised median flow at Fernhill (70,986 litres/second). (The naturalised median flow is what the river level would be if there was no abstraction.)
Hawke’s Bay Fruitgrowers’ Association president Lesley Wilson says the low flow limit of 1581 litres/second would leave no irrigation water at all for horticulture on the plains. Municipal takes for Napier and Hastings cities would also come out of this volume, and there would be nothing left over.
Hawke’s Bay grows 70% of all the apples in New Zealand and in the next few years that will equate to $700 million dollars being poured into the Hawke’s Bay economy.
“Food security and jobs are put at risk by the proposed WCO. Remember that one-quarter of all people employed in New Zealand is reliant on exports. The impact on Hawke’s Bay is immense; under this proposal we might as well just pack up and go away.”
In a water restriction, the first priority is for people, and then followed by water for stock; there would be no water left over for trees. New science just released by the Hawke’s Bay Regional Council indicates all of the water, surface and groundwater, on the Heretaunga Plains is connected. The timing of the WCO and the new science means any restrictions placed would be far reaching.
Lesley says the WCO is a blunt and outdated instrument that only covers the environmental aspects affecting the river. The order undermines a process she, and other primary industry representatives, Xan Harding for Hawke’s Bay Winegrowers and Bruce Mackay for Heinz-Wattie’s have put a great deal of faith in. All parties belong to TANK, the acronym stands for Tutaekuri, Ahuriri, Ngaruroro and Karamu catchments, plus the Heretaunga Plains, which brings all interested parties to the table to plan the best way forward for managing water on the Heretaunga Plains. Land and water resources are under review in the greater Heretaunga and Ahuriri area.
TANK is a critical part of that review process; it focuses on water quality, flows and allocations in the four catchments, including for wetlands and estuaries. This catchment-wide approach to managing water and land would ultimately lead
to Regional Resource Management Plan (RRMP) changes. The greater consultative effort was in part, to avoid a similar situation to Twyford, where water users were unprepared for wide-sweeping changes to their water allocations.
Five parties combined to an application for the WCO for the Ngaruroro and Clive rivers with the Minister for the Environment.The applicants are the New Zealand Fish and Game Council, the Hawke’s Bay Fish and Game Council, Ng-ati Hori ki Kohupatiki, Whitewater New Zealand, Jet Boating New Zealand, and the Royal Forest and Bird Protection Society of New Zealand.
The applicants seek protection of:
• The entire length of the Ngaruroro River.
• The tributaries and hydraulically connected ground
water to the Lower Ngaruroro River.
• The 7km-long Clive River.
The basis for the application is for “cultural and spiritual purposes, to protect trout and native fish, and for boating and recreation”. A WCO is akin to applying for national park status to a body of water. Severe water restrictions along the length of the river would have dire consequences for horticultural users.
The application for the WCO was lodged at the end of 2015; more than a year lapsed, then the Minister appointed a special tribunal in February 2017. The tribunal then notified the submission and called for applications in July, giving submitters just 20 working days to respond to the tribunal.
The next step is an Environment Court hearing, which then makes a recommendation to the Minister who in turn would make a recommendation to the Governor General, who would make an order of council if the application was successful.
Fifteen water conservation orders are in place in water bodies in New Zealand, with three more currently submitted for consideration.
The Ngaruroro River has its origins in the Kaimanawas, runs into the Kawekas then through farmland, and horticultural land before it reaches the Pacific Ocean. For the purposes of the WCO, it is divided into three distinct sections. The Upper Ngaruroro is largely untouched, running through forest park
to Whanawhana (45kms), a section that is not opposed by horticultural users. At this point the river changes from single channel through greywacke gorge to a braided river. North of Whanawhana the river is largely in its natural state, and supports 13 species of endemic native fish, 9 native species of invertebrates and 44 native bird species.
The middle section between Whanawhana and the Chesterhope Bridge at Pakowhai (50km long) is the longest example in the North Island of a braided river. It similarly supports native species including New Zealand’s unique torrent fish.
Recharge to the Heretaunga aquifer system comes from the Ngaruroro system; this provides municipal water for 80% of the regional population, and underpins horticulture on the plains.
The final section, the Lower Ngaruroro River – Clive River section underwent a major realignment in 1969 as part of the Heretaunga Plains Flood Control System. Ng-ati Hori ki Kohupatiki live along the edge of the Clive River at Farndon near the township of Clive.
Fish & Game calls for an increase in the low flow limit from 2,400 litres/second to 4,200 litres/second at Fernhill in its application. At a 2,400 litre low flow, a one in 10 year drought would lead to bans being placed. At the raised level of 4,200 litres, bans would come into place every other year, or 1 in 1.7 years.
A possible 222 unconfined Ngaruroro groundwater takes expiring in May 2019 could be reclassified as stream depleting, however new science linking all groundwater would create a ripple effect to all horticultural users.
The WCO request for a low flow allocation of just 1,581 litres/ second at Fernhill is in stark contrast to the current allocation for surface takes only is 5,743 litres/second, a massive over allocation of 4,162 litres/second. These figures were prepared by Irrigation New Zealand North Island project manager Vicky Bloomer, who says the effect if groundwater takes were also taken into account would be massive.
Grave restrictions are also placed by the WCO on water taken for storage; water can only be drawn from the river when flow is above 70,986 litres/second. In the 2016-17 growing season, there were only 48 days when river flows were high enough to draw for storage, and these were during flood events when the water contained high sediment levels.
Irrigation NZ in its submission to the EPA has supported the WCO status for the Upper Ngaruroro above Whanawhana.
LOWER NGARURORO GREATLY MODIFIED
The lower Ngaruroro River and Clive Rivers are highly modified environments. A drainage and flood control scheme has been established on both rivers since the late 1800’s, and has been expanded over time to now include:
577 km of river, stream and drainage channels.
287 km of ‘live edge protection’ – to reduce erosion and slow flood waters.
196 structures including, culverts, floodgates, control gates, weirs, rock groynes and pipelines.
5 detention dams.
18 pump stations, 7 mobile pumps and 2 emergency generators.
155 km of stop banks and deflection banks.
Approximately 760 ha of land, including river berms and land underlying other scheme assets.
The scheme provides flood control and drainage benefits for approximately 39,000 hectares of premium horticultural land along, with protection for approximately 127,000 people.
All fruitgrowers, wine growers, grower organisations and related industries were called upon to submit to the Environmental Protection Agency prior to the August 24 deadline to engage in the consent process.
“The scheme provides flood control and drainage benefits for approximately 39,000
hectares of premium horticultural land along,
with protection for approximately
The Heretaunga aquifer is shaded in blue.