Operative Waikato Regional Policy Statement (October 2000)

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3  Significant Resource Management Issues, Objectives, Policies and Methods

3.4  Water

3.4.3 Ground Water Resources

The ground water resources of the Region can be grouped into five categories based on the geology of the major aquifers:

1. Basalt aquifers are found in the Tuakau, Pukekohe and Pukekawa areas. Water quality is high, as is local demand.
   
2. Rhyolite and coastal sands are found in the northern Bay of Plenty and Coromandel areas. Ground water supply is variable and demand is generally low. However, in some parts of the Peninsula, availability is an issue. Other issues include salt water intrusion, and bacterial contamination. Sewage disposal via septic tanks has also caused contamination in some coastal margins.
   
3. Ground water yields from sand and gravel aquifers in the Hamilton and Hauraki Basins are variable and demand is moderate. Ground water quality is of concern as a result of the high natural iron and mineral concentrations and pollution from pastoral farming, horticulture and effluent discharges can cause high nitrate levels in some places¹.
   
4. Ground water yields and demand are low from the greywacke and limestone aquifers of the west coast catchment.
   
5. The Central Volcanic Plateau is dominated by pumice and ignimbrite. The ground water in this area is naturally high in phosphorus; yields are moderate; quality is high; and demand is generally low to moderate.

It is necessary to make the distinction between ground water and geothermal water as they relate to this section. Geothermal water is defined in the RMA as meaning water heated within the earth by natural phenomena to a temperature of 30 degrees Celsius or more; and includes all stream water, and water vapour and every mixture of all or any of them that has been heated by natural phenomena. Therefore geothermal water is not always strictly ground water in all of its states. Geothermal water as defined is governed by section 3.7. All other water outside the coastal marine area is governed by section 3.4.

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Footnotes

1. Selvarajah et al., Nitrate in Ground Water in the Waikato Region, 1993.