This page contains information about the considerations for providing physical infrastructure due to growth in the District's population and economy.
22/07/2010 12:49 p.m.
The affected infrastructure
Growth in our economy and population requires considerable investment in infrastructure and services. The spatial arrangement of development has major implications for the provision of physical infrastructure. There is potential for substantial costs to Council, the business sector and the community. Continued widely dispersed development and settlement patterns have effects on both the timing and costing of hard infrastructure, including:
- solid waste.
We rely heavily on private cars for most of our personal travel, and on road vehicles for most freight movement. A widely dispersed settlement pattern requires roading infrastructure to support it.
The scattered distribution of recent development poses problems for the timely and cost-effective provision of roading infrastructure. Subdivision and land development creates demand for both new roading and the upgrading of the existing roading network.
It is difficult to plan for new roads and upgrades of existing roads if the location of future subdivision and development is unknown. In these circumstances the provision of roading infrastructure tends to be reactive rather than proactive. The efficient and timely provision of roading infrastructure requires integrated transport and land use planning.
Urban Whangarei is faced with severe capacity and congestion issues, particularly in the Whangarei CBD area. Increased traffic counts on all parts of the roading network are putting additional strain on the Whangarei urban network which is already operating well beyond its design capacity.
With increasing growth pressure, this will continue impacting on the local community and the wider regional economy as the Whangarei urban area is a major bottleneck for through traffic to the east and west coast communities of the region and to destinations north and south of Whangarei.
Currently, the water supply infrastructure provides potable water to approximately 80% of the district’s population. Increasing population and industrial growth is placing pressure on Whangarei’s stored raw water, meaning our ability to meet the 1 in 50 year drought scenario is becoming strained. In other words, if the city’s water needs continue to rise at current rates Whangarei will be left exposed to water shortages in times of drought. Some issues are as follows:
- the total annual water consumption is expected to increase from 6.868 million to 8.156 million cubic metres annually in 2055.
- sustainable water savings can be implemented until 2025 to make up the shortage in supply during a 1 in 50 year drought. However, as the population continues to grow and the climate is predicted to get warmer, a new water source remains a vital requirement for the Whangarei Water Supply Area.
- after 2035 the Whau Dam will be completely dry during a 1 in 50 year drought. This will occur earlier if the water leakage is not reduced as planned.
There will need to be a significant investment in water infrastructure in rapidly developing areas, such as Bream Bay and Three Mile Bush.
- it is difficult and expensive to continue the water reticulation system in some inland rural areas and coastal areas if the current out of town development continues without connecting to the town supply thus creating an artificial barrier to the growth of the water supply system.
Major pressure is evident on the wastewater system as a result of growth in the district. The pressure is most evident in the Ruakaka area where major planning work is in progress to build a new wastewater treatment plant and reticulation systems to cater for in excess of 20,000 cubic metres per day of waste, compared to present day flows of around 600 cubic metres per day.
The pressure however extends throughout the district in terms of growth in coastal areas (e.g. Tutukaka and Oakura), and the city catchment. The Whangarei Heads wastewater system presently under construction will relieve some of this pressure north of the Whangarei Harbour.
In Whangarei City centre sewers were laid during the early 1900s. These pipes have an estimated average design life of 50 to 80 years. Comprehensive condition data on these pipelines is not available although the available inspection and maintenance records indicate that a number of sewers are at, or near, design capacity.
This has been exacerbated by the overloading of the sewerage reticulation system during peak wet weather resulting in overflows during extreme events. In short, an upgrade to the city sewer and wastewater treatment plant is needed to cope with high rainfall events and projected population growth within the catchment.
There are ongoing issues with stormwater reticulation. The CBD is already vulnerable to flooding, and any increased flows from catchments which ultimately discharge through the urban streams into the upper harbour will add to the risk in that area.
This means that for further growth, development in catchments which discharge via the CBD will exacerbate existing problems. There are various methods to address flooding in the CBD and WDC is presently examining these and their associated costs.
Stormwater disposal remains a problem throughout the district. Many areas are prone to flooding and land instability. High intensity rainfall and small catchments tend to increase flooding problems and slip damage. Erosion and sedimentation of waterways is problematic as is pollution from both agricultural and urban sources.
Better treatment and/or disposal facilities for stormwater and more riparian plantings are needed to address these issues. Projected growth in both urban and rural areas will require detailed stormwater management plans.
Waste generation is closely linked to population growth and industrial development which means more development will result in greater waste generation. Council currently transports all residual waste out of the district to Redvale Landfill located in Silverdale, north of Auckland, under a 5 year contract. This contract expires in October 2010.
Council always intended to review other options including the establishment of Puwera Landfill as an alternative to transporting waste out of the district. Continuing to transport refuse to Redvale Landfill is not Council’s preferred option. It could lead to a near monopoly situation and the waste sector in Northland could become increasingly controlled by the private sector. This may limit Council’s ability to influence waste reduction and diversion, which are key elements of its Waste Management Plan.
Electricity and telecommunications
Other infrastructure services such as electricity and telecommunications will be able to cope with the growth demand given these services are installed at the time of land subdivision and development.
However, further work at a national level may also impact on Council such as a proposed National Environmental Standard on telecommunication facilities in road reserves.
Fast broadband connection remains an issue in Whangarei District (and Northland) although this may be addressed by the planned upgrade of infrastructure by NRC and NorthPower.
Security of power supply remains an issue for Northland. Expansion of the Ngawha geothermal station and planned tidal generation in the Kaipara Harbour will assist in this regard.
There is also potential, particularly in the Far North and on the West Coast, for wind generation.
Select from the following links to read about the other key issues.
Environmental EffectsSocial and Cultural Wellbeing