Operative Waikato Regional Policy Statement (October 2000)

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3  Significant Resource Management Issues, Objectives, Policies and Methods

3.4  Water

3.4.4 Significant Resource Management Issues

This section briefly sets out the significant water resource management issues for the Waikato Region. Issues have been grouped under the following categories: water quality, flow regimes, allocation, wetlands, public access and matters of significance to iwi.

The quality of the Region’s waterways is generally high in upper catchments but degrades downstream, particularly in intensively used catchments. Loss of habitat, degradation of aesthetic characteristics, siltation, and excessive concentrations of nutrients are of particular concern. Toxic substances are also emerging as an issue of concern in some specific areas.

Figure 3 presents the principal effects of surface water contamination and their importance from different sources. The sources are grouped into point sources (e.g. discharge of waste from a pipe) and non-point sources (e.g. runoff from land).

Point sources such as sewage treatment plants and industries contributing wastewater and/or stormwater are commonly considered as the major contributors to pollution. In recent years efforts have been focused on improving these larger point source discharges. Numerous small point source discharges, such as dairy farm effluent and acid mine drainage from abandoned mines, can result in cumulative adverse effects.

Contaminated sites, leachate from mine tailings and waste rock disposal facilities, leaking underground storage tanks, inappropriately designed and/or poorly maintained septic tanks and land treatment systems for sewage and other wastes are also of concern. Whilst such contamination is attributable to a single source, the impacts can be widespread and locally severe.

It is now recognised that the cumulative adverse effects of non-point sources, such as agricultural runoff, can far outweigh the waste loadings and associated environmental effects of large discharges. The effects of these non point discharges are particularly notable in intensively farmed catchments where waterways have elevated levels of nutrients, faecal bacteria and sediment. Indeed, non-point sources are now considered to be the dominant cause of reduction in water quality in the Region. They are, however, much more difficult to identify and remedy than point sources. A good understanding of land-water interactions, combined with an integrated catchment-wide approach is essential for the management of non-point sources.

The loss or modification of riparian vegetation along the banks of waterways, soil erosion from vegetation clearance and land disturbance, and the draining of wetlands have contributed to the sedimentation and nutrient enrichment of waterways. These activities have also caused a significant reduction in aquatic habitat, and in many cases increased water temperature, modified stream flows and increased flood risk. Riparian vegetation acts as a natural filter of organic matter, nutrients, and sediment. Vegetation can also stabilise stream banks and provide shading of waterways.

Urban stormwater runoff also has adverse effects on water quality, contributing sediment and potentially toxic contaminants (such as lead and hydrocarbons) to waterways.

The dominant issue in shallow aquifers in intensively farmed areas, including the Hauraki Plains, Lower Waikato, and Hamilton Basin, is the presence of high levels of nitrate. Levels several times above that recommended by the New Zealand Drinking Water Guidelines (Department of Health, 1994) have been recorded around Hamilton. Excessive nitrate levels can be toxic for humans, particularly infants. High nitrate levels can also affect the quality of waterways and lakes in discharge zones.

Figure 3: Principal Effects of Surface Water Contamination and their Importance from Different Sources

The availability of sufficient water is crucial for consumptive as well as instream uses. Water abstractions (particularly during periods of low flow) and impoundments have major effects on water flows in the Waikato Region.

The cumulative effect of multiple water takes, (for example, for irrigation of market gardens in the Pukekohe area) results in lower water flows in streams, thereby causing reduced assimilation of wastes, increased temperature and nutrient levels, reduced oxygen levels, and modification of aquatic habitats. There is a need to carefully manage the takes from water bodies to ensure that they do not have adverse impacts on the natural and physical resources of the Region. As the Waikato Region is increasingly facing periodic seasonal shortages of water it is necessary to make provision for such shortages in water allocation strategies.

The need for the control and regulation of dams depends on their size and location. The beneficial effects of impoundments (electricity generation, flood control, recreational activities in lakes created by the impoundments) must be balanced against changes in water quality, loss of habitat and associated aquatic life, the disruption to natural migration of fish species, the reduction in some cases of recreational opportunities and scenic values in comparison with its natural state, and the loss of cultural and spiritual values. Even small dams (e.g. for stock water supply) in sensitive and/or highly valued catchments may be of significant concern. However, off-stream impoundments or those on ephemeral water courses generally have minimal environmental effects.

Ground water is an integral part of the water cycle. Any activity in one part has an effect on other parts (e.g. extensive use of ground water resources may reduce the flow of surface waters and cause degraded water quality and loss of stream habitat). If abstractions exceed the recharge ability, mining of the ground water resource occurs. Due to seasonal as well as longer term fluctuations in water levels, the effects of ground water mining can be considerably delayed. Land use can also reduce the amount of water in an aquifer, for example through the sealing of large areas for subdivisions which reduce the amount of water available for infiltration. Drainage causes a lowering of the ground water table by diversion of water (see section 3.2.10 Moisture Management).

The benefits of maintaining ground water levels include:

1. prevention of salt water intrusion into ground water aquifers
   
2. adequate recharge of deep aquifers and discharge into surface water catchments, particularly during summer
   
3. maintenance of a sustainable yield for existing and potential future uses, including community water supplies, agriculture, industry and domestic supplies.

Competing water uses can result in water shortages and conflicts. The efficient use of water may reduce these conflicts of use and increase water availability to a range of interests both now and in the future.

The efficient and effective use of the water available for out of stream use is a significant resource management issue. Water which can be taken from water bodies without producing significant adverse effects is finite. There are a number of competing demands for use of the Region's freshwater resources and during certain times demand for this water has the potential to exceed supply. There is a need to ensure that the available water, which can be taken, is apportioned in a way which ensures that the greatest efficiency is obtained, particularly in the case of water bodies subject to the greatest demands.

Wetlands are now one of New Zealand’s rarest and most at risk ecosystems. It has been estimated that less than ten percent of the indigenous wetlands of the Waikato Region remain. Of the many distinctly different types of wetlands, a diverse representation can be found in the Waikato. However, some of these wetlands can only be described as remnants.

Protection of remaining wetland areas is an important issue. Unmodified wetlands provide substantial ecological and social benefits including:

1. maintaining good water quality by storage of contaminants and/or transformative processes
   
2. prevention/mitigation of shoreline erosion and sedimentation
   
3. reduction of drought and flood risks
   
4. recharge of ground water supplies
   
5. provision of food and habitat for a wide variety of indigenous plants, waterfowl, fish and other wildlife, including rare and endangered species
   
6. recreational, educational, scientific and aesthetic opportunities, spiritual and cultural values.

Lowland wetlands have faced the most pressure, mainly from drainage and agricultural development. Drained peatland areas form a significant portion of the Region’s dairying farmland.

Although the larger wetland areas within the Region such as Whangamarino and Kopoutai are significant, some of the most important wetlands are small and contribute significantly to the quality of water. Also see section 3.11.2 Flora and Fauna (Biodiversity).

The maintenance and enhancement of public access to and along lakes and rivers is a matter of national importance that must be provided for in Regional Policy Statements. Such access will provide for the use and enjoyment of the amenity, scenic, and recreational values of rivers and lakes, and for the cultural and spiritual values and customary uses of tangata whenua.

Restrictions on public access occur for various reasons, including private ownership of river banks and lake edges. In this Region a significant proportion of land adjacent to water bodies is in private ownership and public access is therefore at the discretion of the land owner. To enable the public to enjoy the amenity and recreational values of rivers and lakes it is important the restriction of public access over public land occurs only for good reasons, for example public safety and legislative requirements.

It is recognised that there will be opportunities to enhance access to certain water bodies with changing land use patterns. These opportunities should be recognised and provided for by territorial authorities in their district plans. Requirements for esplanade areas are the most appropriate means for achieving this. It is recognised, however, that there are limits to resources within the Region and providing access to all rivers and streams may be impractical. Private landowners are also generally willing to provide access along their properties as long as their property and stock are protected.

Mauri has been described as a special power possessed by Io⁴ which makes it possible for everything to move and live in accordance with the conditions and limits of its existence. Everything has mauri, including people, fish, animals, birds, forests, land, seas, and rivers; the mauri is that characteristic which permits these living things to exist within their own realm and sphere⁵. Each iwi group has their own concept of mauri, however it is generally referred to in English as life-force, life-essence or life-principle (essentially having spiritual qualities).

The term taonga is used in s6(e) of the RMA and Article two of the Treaty of Waitangi. It defines things of value to tangata whenua and is generally interpreted as anything 'highly prized' and includes both physical resources such as eel fisheries and spiritual resources, such as the relationship Maori have with water resources.

Maori traditional practices, through the exercise of kaitiakitanga, maintain and enhance the mauri of physical and spiritual resources. All persons exercising powers and functions under the RMA, in relation to managing the use, development and protection of natural and physical resources, are required to have particular regard to kaitiakitanga (s7(a)). Kaitiakitanga involves a broad set of environmental practices and principles developed by tangata whenua to cater for their specific iwi, hapu and whanau needs.

Tangata whenua who hold mana whenua are kaitiaki over natural resources within their tribal boundary. The maintenance and enhancement of mauri is significant to tangata whenua with respect to the sustainable management of water. Kaitiaki formalised tikanga, i.e. practices and restrictions, for the sustainable management of natural resources. Tikanga, or practices were developed by and observed by kaitiaki to maintain and enhance the health and diversity of the mauri of natural and physical resources so that the resources would continue to provide benefits for future generations.

The discharge of contaminants to surface and ground water has the effect of diminishing the mauri of water if the health, abundance and diversity of life forms and food sources is reduced. Historically, the disposal or discharge of contaminants has not been managed in a manner consistent with Maori values or concerns. However, with an increase in community awareness of the adverse environmental effects of these activities, practices for contamination disposal have improved within the Region. As a result, water quality has improved which has led to an enhancement of the physical and spiritual attributes of the water.

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Footnotes

1. Loss and modification of habitat not included.
2. Due to toxic effects of ammonia on fish and other aquatic life.
3. Significant proportion of toxic contaminants in urban stormwater is derived from motor vehicles (e.g. lead, zinc, copper, and hydrocarbons).
4. See glossary for definition of Io.
5. Barlow 1991, p83.