Regional Policy Statement for Taranaki |
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| This page: | Part B Section 6.3 — Groundwater |
6.3 Maintaining groundwater flows and quality at sustainable levels
Background to the issue
There are four principal groundwater aquifers in the Taranaki region - the Matemateaonga Formation aquifers, Whenuakura Formation aquifers, Marine Terrace aquifers and the Taranaki Volcanics aquifers. However, while groundwater resources in the region are significant, considerably less is known about this resource compared with surface water (particularly those at depth). Yields are also relatively low, compared with other regions.
Most groundwater use in the region is for stock and domestic purposes, which generally involves small volumes and low rates of extraction with no significant adverse environmental effects. Other significant groundwater use is for industrial purposes, community water supply, and pastoral and horticultural irrigation.
Even though use of groundwater in Taranaki is low compared with many other parts of the country, it is increasing. Short term fluctuations in groundwater levels are normal and do not necessarily indicate that groundwater abstractions are unsustainable. However, a long-term decline in groundwater levels could occur if abstractions exceed the natural recharge of the resource. Reduced groundwater levels not only affect the aquifer but can also cause interference between adjacent wells or bores and affect flows and levels in nearby surface water bodies.
Groundwater quality in Taranaki is generally good, although there are some variations due to local geology and the influence of intensive agricultural land use on shallow unconfined aquifers in the Taranaki volcanics and marine terraces. Point and diffuse source discharges from industrial, agricultural and domestic activities to groundwater may result in declining groundwater quality (eg, elevated nitrate levels in unconfined, shallow groundwater), which in turn can impact on existing and potential groundwater users. Groundwater abstractions can also lead to the inflow of poor quality recharge water or seawater (where in close proximity to the sea). Microscopic biota in groundwater may play a role in the protection of groundwater quality.
Deep well injection of production water and other exploration waste to deep confined aquifers below the fresh water and salt water interface is a reasonable and appropriate method of disposing of waste providing appropriate safeguards are taken.
The significant issues in relation to maintaining groundwater flows and quality are:
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GWR |
Managing adverse effects on groundwater flows arising from over abstractions.
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GWR |
Managing adverse effects on groundwater quality arising from land use, the discharge of contaminants, and poor well and bore siting and construction. |
Objectives
GWR OBJECTIVE 1
To sustainably manage the use of groundwater in the Taranaki region by:
(a) enabling people and communities to take and use groundwater to meet their needs while avoiding, remedying or mitigating adverse effects arising from that use; and
(b) avoiding, remedying or mitigating adverse effects on groundwater quality from over abstraction, intensive agricultural land uses, the discharge of contaminants, and poor well and bore construction.
GWR OBJECTIVE 2
To improve knowledge of groundwater resources in Taranaki to promote the sustainable management of groundwater resources.
Policies
Sustainable yield
GWR POLICY 1 The groundwater resources of Taranaki will be managed on a sustainable yield basis to prevent adverse effects on groundwater levels and yields and groundwater quality.
Taking and use of groundwater
GWR POLICY 2 Groundwater allocations will be made having regard to: (a) the need to maintain a sustainable yield of the aquifer; (b) the need to ensure groundwater is available for reasonable domestic needs, stock watering requirements and fire fighting purposes; (c) the need for the volumes sought; (d) the need to use water efficiently and with a minimum of waste; (e) the need to avoid the inflow of poor quality water into aquifers; (f) the need to avoid saltwater intrusion into aquifers; (g) the need to avoid significant interference with existing lawfully established and sustainable water uses; (h) the cumulative effects of existing takes from the aquifer; (i) the degree to which the abstraction may impact on nearby surface water bodies and surface water takes; and (j) the need to install systems to accurately measure the volumes of water abstracted.
Alternative to use of surface water
GWR POLICY 3 The use of high quality groundwater for community and industrial supply will be promoted as an alternative to the use of surface water resources, provided that any adverse effects arising from the use of groundwater are avoided, remedied or mitigated.
Groundwater quality
GWR POLICY 4 Groundwater quality will be maintained and enhanced by: (a) managing the discharge of contaminants to land and water such that any actual or potential adverse effects on groundwater quality are avoided, remedied or mitigated; (b) managing the siting, drilling, construction or alteration of wells and bores; (c) managing old, damaged and unused wells or bores; (d) controlling deepwell injection of wastewater or other contaminants to groundwater to ensure there is no significant risk of degradation to useable groundwater resources; and (e) promoting land use practices that minimise as far as practicable the potential for adverse effects on groundwater quality.
Explanation of the policies
Policy 1 states that groundwater in Taranaki will be managed on a sustainable yield basis. The concept of sustainable yield applies to both the quantity and quality aspects of groundwater and is the quantity of groundwater that can be abstracted from an aquifer for a prolonged period without depleting the resource or causing other adverse effects on groundwater quality or groundwater users.
Policy 2 identifies those matters to be considered in relation to the taking and use of groundwater. These matters include consideration of sustainable yield, flow depletion and the avoidance, remedying and mitigating of other adverse effects on the environment. The policy recognises the connectivity between surface waters and groundwater by having regard to the degree to which an abstraction of groundwater might impact on surface water bodies or surface water takes. The Policy states that groundwater is to be available for reasonable domestic needs, stock watering (for cattle, pig, poultry and other livestock) and fire fighting. This reflects the requirements of section 14(3) of the Act.
The use of groundwater for community water supplies is important to enable people and communities access to essential water resources. Other users may benefit by connecting to community water supplies. This provides for better quality construction of bores, better control of abstraction and monitoring of aquifers and improved security of the aquifer from contamination.
Policy 3 recognises demands on surface water quality resources and seeks to promote the alternative use of high quality groundwater for community and industrial supply - subject to any adverse effects arising from the use of groundwater being avoided, remedied, or mitigated.
Policy 4 addresses the maintenance and enhancement of groundwater quality. The policy aims to prevent aquifer cross-contamination and aquifer contamination from the surface due to open or unsealed bores or wells, or contamination from drilling activities or waste disposal activities (whether surface or sub surface). It also involves promoting land use practices and managing the discharge of contaminants to land and water to avoid, remedy or mitigate adverse effects on groundwater quality. This is particularly an issue in major aquifer recharge zones especially those used for community water supplies. Bores sharing the same aquifers as community supplies, especially those further up the aquifer should be constructed to the same standard as required by the Ministry of Health for community supplies.
Related policies
All policies relating to Section 5.1 [Soil erosion] and Section 5.2 [Soil health]; Policy 3 of Section 6.1 [Surface water allocation]; Policy 1 of Section 8.1 [Preservation of the natural character of the coastal environment]; Policies 1 and 2 in Section 9.1 [Indigenous biodiversity]; Section 13 [Minerals]; Policy 1 of Section 15.2 [Regionally significant infrastructure]; and all policies relating to Section 16 [Issues of significance to iwi].
Methods of implementation
The Taranaki Regional Council will:
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GWR METH 1 |
Maintain a regional plan or plans with objectives, policies and methods of implementation addressing the taking and use of groundwater and the discharge of contaminants to groundwater.
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GWR METH 2 |
Apply regional rules to allow, regulate and avoid adverse effects on the environment from the taking and use of groundwater and the (direct or indirect) discharge of contaminants to groundwater.
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GWR METH 3 |
Provide advice and information, including guidelines, to landowners, resource users and the public: (a) to generally promote awareness of groundwater issues; (b) to promote the conservation and efficient use of groundwater; (c) on systems, siting, design, installation, operation and maintenance procedures for groundwater takes and land disposal systems; (d) on land use practices that minimise the potential for adverse effects on groundwater quality; and (e) to promote the sustainable use of deep groundwater for community and industrial supply.
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GWR METH 4 |
Advocate as appropriate to manufacturers and suppliers of agrichemicals, fertilisers and other agricultural compounds, the strengthening of the education and information provision role they play with a view to minimising the likelihood and potential effects on groundwater quality of the application and use of agrichemicals, fertilisers and agricultural compounds.
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GWR METH 5 |
Encourage, as appropriate: (a) water harvesting, the use of storage reservoirs or impoundments to store water at times of high water flow, or the collection or storage of rainwater; and (b) the adoption of water saving practices and the use of water saving devices, water metering, water recycling and the use of more efficient plant or manufacturing processes.
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GWR METH 6 |
Monitor and gather information on the state of groundwater flows and quality, pressures on groundwater flows and quality, and responses to management.
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Territorial authorities may wish to consider the following method:
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GWR METH 7 |
Promote the location and sustainable use of groundwater for community and industrial supply. |
Principal reasons for adopting the objective, policies and methods
The objective, policies and methods of implementation establish a policy framework for maintaining groundwater flows and quality in the Taranaki region. Their aim is to maintain Taranaki's generally high to excellent groundwater quality.
In respect of addressing groundwater issues, the policies and methods focus on regulatory methods (complemented by a mix of non-regulatory methods). Regulation, through the inclusion of rules in the Regional Fresh Water Plan for Taranaki and conditions on resource consents relating to the siting and management of bores and wells, is a simple, efficient and effective method of controlling adverse effects associated with the taking and use of groundwater and deepwell injection. Other methods such as information provision will also be useful tools in achieving the objective, particularly in relation to diffuse source discharges to groundwater. These methods are considered to be the appropriate approaches having regard to their efficiency and effectiveness and their benefits and costs.
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Environmental results anticipated GWR ER 1 Provision for the needs of consumptive water users. GWR ER 2 Takes of groundwater that do not exceed the sustainable yield of aquifers. GWR ER3 Maintenance of good to excellent groundwater quality against accepted national standards comprising physical, chemical and biological measures of water quality. |