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Hawke's Bay region

Groundwater Zone: Heretaunga (TANK)

The Heretaunga Plain aquifer is the largest groundwater resource in Hawke's Bay and has been identified by the Ministry for the Environment as a national water body of the highest economic value. 

The Heretaunga basin includes about 1800 groundwater consents representing approximately 80% of all the Hawke’s Bay groundwater consents and 63% of the consented weekly volume. The main groundwater use is for irrigation and municipal supply. Groundwater levels in the Heretaunga Plains have been monitored for over 45 years, over this period there has been a slow decline in water levels and a gentle increase in the amplitude of seasonal fluctuations.

The Heretaunga basin is subject to a current plan change process known as TANK as it refers to the main catchments on or crossing the Plain - the Tutaekuri, Ahuriri, Ngaruroro and Karamu -

The Heretaunga basin is about 320 km2 and about 300 m deep consisting of at least 5 to 7 primary aquifers that formed during the last 250,000 years. Sediments from the Tutaekuri, Ngaruroro, and Tukituki rivers together with coastal, lagoon, estuarine and embayment deposits have formed both confined and unconfined aquifers.

At the western most edge of the basin (to about Hastings) the aquifer system is predominantly unconfined with thick alluvial gravels of up to 50 m thick. Toward the east, the aquifer becomes progressively confined and overlain by layers of clay and silt deposits. Seismic interpretations from the Mason Ridge oil exploration test bore suggest the basin is thickest near Flaxmere with an approximate thickness of 400 metres.

Water Use
Groundwater in this zone

Regional councils collect information about how much water is available and manage resource consents for those wishing to take water from groundwater supplies. Use the buttons below to view regional information on: how much water is available, where it comes from and how its used.


Groundwater available: {{waterSource.availableToAllocate}} Irrigation
Town supply
  • Groundwater in this zone
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    Groundwater in this zone

    Accurately estimating the total amount of water available in a groundwater management zone is not currently possible. Regional Councils are working with the Ministry for the Environment on the best way to calculate this figure. We will include these figures on LAWA when they become available. In the meantime, for more information about a particular groundwater management zone, contact your regional council.

  • Water consents: How much water is consented and used?

    Groundwater available to consent

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    Consented water in this groundwater zone

    Use the tables below to look at how much water is available compared with how much is actually consented within this water management zone. Click the plus to expand subzones where available

    Comparing consents and use
    Amount available to consent In this groundwater management zone:
    {{}} {{}}
    available to consent
    Amount consented
    measured and non measured
    Amount used (measured)
    Amount Units Consented or used as a percentage of available
    Total available to consent {{}} {{}} {{}}
    Total consented {{}} {{}} {{}} {{}}
    Total consented and measured {{}} {{}} {{}} {{}}
    Total measured amount used {{}} {{}} {{}}
    Total measured volume used {{}} {{}}

    The table above shows the amount of water that is available for use compared to the amount that has been consented. The ‘Total Consented’ and ‘Total Consented and Measured’ fields are based on percentages of the ‘Total available to Consent’ field. If this field is not populated no data will be displayed. Some consents require actual use to be monitored and this is presented as 'Total measured volume Used' where available.

  • Water consents: How is consented water used?

    Consents by use in this groundwater zone

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    Consented water in this zone

    Overall annual volume for {{waterAvailable.year}}
    Relative breakdown
    Activity Percentage of total consented Total volume Number of consents
    {{item.displayText}} {{item.displayText}} - - No data available {{item.breakdownPercentage}}% {{item.totalVolume}} m3 {{item.numberOfConsents}}
    Total {{}}% {{}} m3 {{}}

    The above table shows the proportion of water consented for irrigation, industrial, stock, town supply and other. It excludes hydro electricity. In this region/management zone {{hydroUsage.totalVolume}} m3/year is consented for hydro-electricity and makes up {{hydroUsage.percentageConsented}}% of the total water volume consented for this region/management zone


Monitored sites in this Zone

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