Unitary Plan issue
We expect natural resources to be available on demand and to use our coastal resources for a wide variety of purposes. However, the combination of decades of urban expansion, high private vehicle usage, and other factors such as poor land and water management practices, have placed increasing pressure on our land and water, reduced air quality, and increased risks from flooding and land instability.
We need to sustainably manage the multiple values and pressures on our natural resources not only for Auckland’s environmental well-being but also for our social, economic and cultural well-being.
Explanation
Maintaining, restoring and enhancing a high quality natural environment is important for our economic prosperity, tourism, and for making Auckland an attractive place to live and invest.
Economic development brings particular challenges for resource management in terms of addressing the environmental impacts of development. We need to make provision for development, significant infrastructure, wastewater disposal, stormwater and discharges to air. We have to manage natural resources such as water, aggregates, soil, and coastal resources in ways that minimise the impact on the environment and communities.
Freshwater systems
Auckland’s natural freshwater systems are susceptible to adverse effects from urban and rural land use and development. Many of our rivers, streams, wetlands and their margins have been permanently lost or fragmented through infilling and piping, or degraded as a result of land use and development practices. This has led to a loss of biodiversity and the important community, cultural and natural values that freshwater systems provide.
Development needs to be appropriately managed so that these important natural and community resources are not lost or further degraded.
Water quality
The quality of Auckland’s fresh and coastal waters can be degraded by urban and rural land uses. Unless appropriately managed, future development may increase existing effects and degradation.
Stormwater runoff is a significant cause of degraded fresh and coaster water and sediment quality in urban areas. Contaminants like sediment, metals and hydrocarbons from buildings, roads, carparks and other hard surfaces are carried in stormwater to groundwater, rivers, streams, estuaries and harbours where they affect aquatic life. Pollutants from industrial sites, or even everyday activities like painting or house washing, can also affect water quality.
Parts of central Auckland are still serviced by a combined stormwater/wastewater sewer system which is designed to discharge a mix of stormwater and wastewater. Intensification, ageing infrastructure and poor wastewater connections can also increase the frequency and volume of wastewater overflows which can degrade water quality in our harbours and city beaches to levels that can affect human health, use and enjoyment of these areas.
In rural areas, nutrients from livestock wastewater systems, pasture and fertiliser application can runoff directly into estuaries, tidal inlets, streams and lakes or leach into groundwater. Sediment from land and stream bank erosion, particularly where riparian margins are not present, also degrades fresh and coastal water quality.
Point source discharges are the easiest source of nutrients to control as flows are concentrated and managed. However, diffuse runoff from rural land contributes significantly to sediment and nutrient loads and is more difficult to manage, generally requiring a change in farming and land use practices.
Water allocation
As Auckland grows we will need more water. Growth and constraints on water supply will impact on water supply costs, the resilience of the network and the environment.
The public water supply accounts for 85 per cent of the water take in Auckland. This comes primarily from the Waitākere and Hunua ranges catchment areas, with additional water imported from the Waikato River to meet demand.
Potential availability and suitability of water for specific uses can be reduced by climatic and land use factors. Discharges into fresh water (surface and groundwater) can degrade water quality and affect the amount available for specific purposes. Increases in the frequency and duration of low flows can also reduce the amount of water available, reduce contaminant assimilation capacity, and affect water quality and in-stream biotic health. The long-term effect of climate change on water availability is uncertain.
Taking, using, damming, and diverting water from surface water bodies is required for activities like rural production, however these activities can have negative flow-on effects. They can change flow regimes in rivers and streams, and the water levels in lakes, wetlands, and dam reservoirs. Taking groundwater can result in changed water levels and flows, leading to reductions in spring and stream-base flow, loss of recharge to adjacent aquifers, and salt water intrusion. Damming surface water can create barriers to fish passage.
Due to the long time lag between nutrients from land activities entering the groundwater and being discharged, the nutrient levels in groundwater are likely to increase before we achieve any decrease. This could lead to production problems and a change in availability of water.
High use or removal of water can threaten stream values and create permanent low flows, leading to reduced habitat quality, increased water temperatures and algal growth, and reduced dilution of contaminants.
Soil
The natural forces of erosion, including rain and high winds, can cause slumping and slips that affect both the integrity of soil and water quality as it is the greatest sedimentation contributor.
Land use and lack of protective vegetation can deplete soil as a resource and result in reduced soil productivity, capability and versatility through accelerated erosion and sediment generation.
Hazardous substances and contaminated land
Auckland contains the largest quantities of hazardous substances of any region in New Zealand. In many instances, these are located close to residential areas and valued environmental areas such as the groundwater aquifer system, and the Waitematā and Manukau harbours.
If hazardous substances are not stored, handled, located or transported with proper care they can affect the health and safety of people working and living in these areas and the natural environment. Contamination of soil or groundwater can also affect people's health and safety, limit land use, reduce land value, and degrade ecosystems. We need to identify, assess and manage land disturbing activities on contaminated land to prevent the release of contaminants.
Genetically modified organisms
The outdoor use of genetically modified organisms could adversely affect our environment, economy and social and cultural resources and values. There is a lack of information, including scientific uncertainty, concerning the effects of GMOs in the environment and risks of irreversible adverse effects which could be substantial. We need to adopt a precautionary approach to managing the risks associated with the outdoor use of GMOs.
Natural hazards
Auckland’s growth will increase pressure to develop areas more susceptible to natural hazards. There may be conflict between where people want to live and where they can live safely, for example the north-eastern coastline, adjacent to streams and exposed ridgelines. Some existing development, including infrastructure, is already located on land that may be subject to natural hazards. This needs managing to ensure that the risk is not increased.
The most frequent natural hazards in Auckland are:
•flooding from river inundation and overland flows
•storm surge
•coastal erosion
•land instability.
Natural hazards require spatial and emergency planning to manage potentially harmful events. We need to locate and design new development and infrastructure to address the effects of natural hazards and impacts of climate change.
Flooding has significant effects on people, property and the environment across Auckland, in both rural and urban catchments. Flood hazards include flooding of river and stream valleys, overland flow of stormwater and inundation in areas where the drainage system can become blocked during storm events (flood prone areas). Flood peaks can be heightened by an increase in impermeable surfaces in urban catchments. Risk associated with these hazards is often exacerbated by the inappropriate location of buildings and infrastructure.
Auckland’s geology is a key contributor to land instability hazards. Some of the region is comprised of soft, weak, and poorly consolidated rock that is prone to failure through rainfall or earthquake events. Residential properties and physical infrastructure such as water and wastewater mains are most vulnerable to damage from land instability. They can also cause land instability if constructed inappropriately.
Within Auckland, coastal hazards arise from the erosion of beaches and cliffs, or inundation of low-lying areas from storm surges and tsunami. Future rises in sea levels have the potential to worsen all coastal hazards. These natural hazards may occur individually, or in combination to create a more significant hazard. Managing land use and development in a way that takes account of these factors can reduce risk to people.
Air quality
Clean air is fundamental to our health, well-being and environment. Auckland, compared to many cities in the world, has good air quality. However, air quality sometimes fails to meet the government's national environmental standards for air quality or Auckland Ambient Air Quality standards (AAAQS). Emissions to air can result in elevated levels of particulate matter, nitrogen dioxide and other pollutants which are linked to negative health effects.
The social and economic cost from particulate emissions in Auckland is significant.
The main contributors to air pollution are domestic fires, transport (predominantly motor vehicle emissions), and to a lesser extent, industry. Reduction in emissions from transport has occurred because of better fuel, new vehicle technology and tighter emissions standards. However, these improvements are offset by increases in vehicle numbers, distance travelled, and an ageing vehicle fleet.
Over the years emissions from industry have reduced due to more efficient production methods, better control technology and change to cleaner burning fuels. However, while industry contributions to regional air pollution have reduced, industry emissions can still impact on local air quality.
Adverse effects from air quality can be exacerbated by land use. Population growth in Auckland is intensifying pressure on competing and incompatible land uses. The inappropriate location of activities that discharge pollutants to air or activities sensitive to air discharges can aggravate any adverse effects from air discharges.
Our focus on a compact urban form and improvements through the provision of alternative transport options supported by operating the transport system in an integrated manner can contribute to lowering air discharges and improving air quality.
Link to Auckland Plan
Auckland Plan strategic direction and priorities
Strategic direction 7: Acknowledge that nature and people are inseparable.
•Value our natural heritage
•Sustainably manage natural resources
•Build resilience to natural hazards