Urban infrastructure
Urban infrastructure is what provides the many amenities of urban lifestyles such as drinking water and wastewater services, electricity and transport. While it provides many benefits for our urban communities it can also have adverse effects on the environment.
Here are the current issues regarding infrastructure in Canterbury/Waitaha.
North Canterbury Flood, 2008
Issue: Need for a more resilient transport network
The resilience of our transport network will continue to be tested as extreme events occur more frequently and with greater severity.
Natural disasters such as flooding and earthquakes can have a devastating impact on our transport network. These risks place pressure on our transport links and have the potential to isolate districts or communities. In many instances alternative routes that must be used are indirect, resulting in extremely long detours, or they are unsuitable for certain large vehicles.
These impacts were demonstrated by the flooding of the Rangitata River in late 2019, which effectively cut the east coast of the South Island/Te Waipounamu in two, resulting in disruption to food delivery services to the lower South Island/Te Waipounamu.
The changing climate is expected to increase network vulnerability, with increased exposure to risks associated with sea level rise, coastal erosion and storm surges. Much of the region is low-lying, and key transport corridors (including State Highway 1 and the Main North rail line) are coastal (see Figure 1).
Greater resilience of the transport infrastructure in Waitaha is needed to secure regional and national supply chains.
Current actions or approach
The Canterbury Regional Land Transport Plan (RLTP) was developed by the Canterbury Regional Transport Committee (RTC).
The RTC is a joint committee of the region's councils as well as Waka Kotahi. Developing the RLTP is the primary role of the RTC and is a requirement for each regional RTC across Aotearoa/New Zealand. It is part of the nationwide process in which local councils, regional councils and Waka Kotahi work together to identify the problems and prioritise investment in the land transport network.
The RLTP has put greater emphasis on network resilience as a strategic investment priority. It is expected that road controlling authorities will work to directly address this priority in the future. Find out more on Environment Canterbury’s regional transport planning page.
Figure 1: Key road network linkages in Waitaha
Issue: Production, distribution, and use of energy can have affects on the environment
Energy supply and use is a key economic driver. We rely on energy to keep warm, transport goods, power industries and grow our food.
Energy production can have benefits such as creating recreation opportunities, jobs, and enabling development. However, energy generation, distribution and use can have significant effects on the environment, ranging from the production of greenhouse gases to the disruption of ecosystems.
Energy generation can also affect social values, for example, requiring relocation of land uses or activities and it can also impact cultural values, through things like the reduction in mahinga kai opportunities.
Energy supply and use in Waitaha
Electricity generation
Most of the electricity generation in Waitaha is from hydro-electric schemes.
Most of the electricity generation in Waitaha is from hydro-electric schemes. The Waitaki scheme, which includes eight dams and an extensive network of canals, is one of the largest electricity generation schemes in New Zealand/Aotearoa. We also have smaller schemes such as those operating at Lake Coleridge.
While hydro-electric generation is a renewable energy source, it has many potential impacts including:
- altered fish migration
- increased water velocity
- modified channel form
- loss of species habitat
- damage to banks and floodplains
- increased water temperature
- reduced water clarity
- increased nutrients and sedimentation.
Dams significantly alter landscapes and affect the mauri (lifeforce) of a river and its catchment by preventing the flow of water ki uta ki tai (from the mountains to the sea).
Cultural values can be impacted by hydro-electric generation schemes. Reduced levels of tuna (eel) recruitment, spawning, and migration, impacts on the movement of water for hydrogeneration between and within catchments, and the unnatural mixing of waters are all cultural impacts of hydro-electric generation schemes. In addition, mahinga kai, natural character, wāhi tapu and wāhi taonga, river mouth environment, and ara tawhito ki pounamu (traditional travel routes) can be impacted by hydroelectric generation.
Community amenity and recreational values that may be affected include game fisheries, jet boating, kayaking, camping, water-skiing, windsurfing, bird watching, rowing, and hunting.
When renewable generation supply cannot meet demand, the Waitaha electricity supply is supplemented by diesel and coal-fuelled generation which contributes to climate changing greenhouse effects.
Waitaha is moving towards a more diversified energy generation supply with large-scale solar farm consents having been approved in the Ashburton District and consents being processed in the Selwyn District. A large windfarm is planned on the Mt Cass ridgeline in North Canterbury/Waitaha.
Transport energy
Waitaha is the second highest emitting region in New Zealand
The movement of people and goods relies on the use of transport energy, and oil-based fuel is currently the dominant source of this energy. However, the use of electric vehicles for passenger transport is increasing.
Since 1990, the energy sector's emissions have increased by 31.8 percent, and this growth is primarily a result of road transportation which has increased by 76 percent over this time.
Waitaha is the second highest emitting region in New Zealand/Aotearoa with a significant proportion attributed to transport. Furthermore, the use of non-renewable energy continues to increase (See Figure 2, Amount (TJ) of Energy Consumed, 2009-2018)
With the primary demand for energy consumption in Waitaha and wider New Zealand/Aotearoa being mostly for transport, increased use of public and active transport nodes, consolidation of urban form, and electrification of vehicles is necessary to reduce greenhouse gas emissions.
Industrial thermal energy
Thermal (heat) energy is often required for industrial processes and public services such as schools, hospitals and prisons.
This energy is often generated through the use of boilers which can be powered by electricity, gas, fossil fuels or biomass.
Over time, many sectors have moved to more sustainable or efficient energy sources.
For example, the majority of schools in Waitaha have replaced coal or biofuel boilers with energy heat pumps while the Washdyke industrial park in Timaru has a district energy scheme which uses biofuel (wood chips) to provide thermal energy to a number of businesses within the industrial park.
The use of boilers can cause localised effects such as poor air quality in addition to contributing to greenhouse gas emissions.
Current actions or approach
Waitaki hydroelectric scheme
The National Policy Statement (NPS) for Renewable Electricity Generation recognises the importance of renewable electricity generation to New Zealand/Aotearoa and is strongly enabling renewable electricity generation. The NPS for Renewable Electricity Generation prioritises renewable electricity generation over environmental effects with no directive to avoid generation where the environmental effects cannot be avoided, remedied, or mitigated. Instead, offsetting and environmental compensation measures are encouraged.
The National Policy for Freshwater Management (NPS-FM) 2020 refers to the Waitaki hydro-electric generation scheme and requires us to consider the importance of the Waitaki scheme to Aotearoa. This includes the scheme's contribution to reducing greenhouse gas emissions and to the security of electricity supply.
The Regional Policy Statement, the Regional Land Transport Plan and Regional and District Plans, enable and encourage efficient use of energy through measures such as subdivision design standards, diversification of transport options and restrictions on the use of some fossil fuels.
The Waitaki Catchment Water Allocation Plan recognises and provides for the operation of the Waitaki hydro-generation scheme, with hydro generation enabled particularly where water may already be diverted for other uses such as irrigation.
Figure 2: Consumption of energy in Christchurch City/Ōtautahi is primarily non-renewable, despite supply being largely renewable.
Source: Neo Leaf Global Ltd - Christchurch City Council
Septic tank
Issue: Cumulative effects of onsite domestic wastewater discharges
On-site wastewater discharges can have adverse effects on human health and the environment. Nitrogen contained within effluent discharges can end up as nitrates in soil and groundwater systems. Pathogens such as bacteria, protozoa and viruses are also contained within effluent and can be harmful to humans if ingested.
Subdivision in areas that are not serviced with a community wastewater treatment facility can increase the risk to human health and the environment from the cumulative effects of on-site discharges. One on-site wastewater system might not pose a significant risk in isolation, but the cumulative effects from discharges that are located close to each other can lead to higher concentrations of contaminants.
Current actions or approach
The provision of reticulated wastewater treatment systems is a requirement under the current Canterbury Regional Policy Statement for new subdivision within the Greater Christchurch region and is implemented through subdivision provisions in district plans.
It is not an explicit requirement for the rest of the region, so district plans outside of Greater Christchurch are not obliged to require reticulated systems at the subdivision stage.
The Canterbury Land and Water Regional Plan manages the discharge component of on-site systems, but this does not form part of a holistic assessment on whether subdivision is appropriate in a given location. This is a process that takes place through district plans.
It is difficult to determine at which point in time the cumulative effects from nearby on-site systems may pose a significant risk and become a barrier to obtaining resource consent. Every application is assessed individually, which creates uncertainty.
A resource consent for the discharge from an on-site wastewater system is required from us in situations that are known to pose a risk to the environment or to human health.
These situations include:
- Properties that are smaller than 4 ha
- Properties where groundwater is shallow
- Properties with drinking-water bores located near or down gradient from the proposed site
- Properties within a Community Drinking-Water Supply Protection Zone.
Stormwater drains lead directly to waterways
Issue: Contaminants carried by stormwater
Rainwater can evaporate, become groundwater, or accumulate and flow over land surfaces, becoming stormwater. Stormwater is the water that runs off impermeable surfaces, such as roofs, roads and carparks. It is usually collected by pipe networks and discharged into streams, rivers and the coastal marine area across Waitaha.
While stormwater is originally rain, it picks up and carries any pollutants and debris that are found on impermeable surfaces, such as copper, zinc, bacteria, sediment, oils, flaky roof paint, and rubbish. Sometimes, pollutants are disposed of directly into the stormwater network by activities such as car washing and rinsing of paint brushes.
Stormwater runoff in Waitaha
These contaminants lead to adverse effects in urban waterways and the Coastal Marine Area (including estuaries and harbours).
These effects include:
- Sedimentation and habitat degradation
- Contamination of water and bed sediments to levels that can be toxic to aquatic life
- Human health risk and reduced amenity or recreational use due to contamination.
Stormwater infrastructure has been designed primarily to convey water away from urban areas to manage flooding risks.
Stormwater is typically discharged untreated via pipe and drain networks directly into waterways.
It is estimated that each year, the following amounts of key stormwater contaminants collectively enter the Ōpāwaho/Heathcote, Ōtākaro/Avon, Puharakekenui/Styx, and Huritini/Halswell rivers in Christchurch/Ōtautahi:
- 6,600 tonnes of Total Suspended Solids (sediment)
- 31 tonnes of zinc
- 4.5 tonnes of copper.
Stormwater from new development areas is often treated using swales, basins, wetlands or proprietary treatment devices that remove some of the contaminants.
Legacy issues from decades of urbanisation and stormwater inputs mean that our urban waterways have some of the poorest water quality and ecosystem health in Waitaha.
Watch the video to learn more about stormwater runoff in Waitaha.
Current actions or approach
A joint approach between us and district and city councils is used to manage stormwater. Through the Resource Management Act 1991, our role as the regional council is to manage rivers and catchments. We do this through the Canterbury Regional Policy Statement (CRPS), and the Canterbury Land and Water Regional Plan (CLWRP).
We also monitor stormwater consent compliance. City and district councils are responsible for managing stormwater infrastructure, such as drains, pipes and treatment systems, along with the discharge itself.
In Waitaha we have the Regional Stormwater Forum, a collaborative project between us, district and city councils, Te Rūnanga o Ngāi Tahu, the University of Canterbury and stormwater industry representatives in the region. The forum aims to improve stormwater management planning, best practice design, consenting and associated environmental outcomes in Waitaha.
From 4 October 2023, our role in relation to stormwater is changing. A new water services regulator, Taumata Arowai, has been established and will set performance measures and targets for stormwater infrastructure. Taumata Arowai will also produce annual reports on the environmental performance of stormwater networks and establish a public register of the stormwater networks across New Zealand/Aotearoa.
Regional councils will be responsible for regulating the discharge of stormwater into the receiving environment, and therefore for setting expectations regarding the quality of stormwater discharges and in-stream outcomes to be achieved.