Toi tū te marae o Tāne; Toi tū te marae o Tangaroa; Toi tū te Iwi.
When the domains of Tāne (land) and Tangaroa (water) are nurtured and sustained, so too will people prosper and flourish.
Greater Christchurch relies on its healthy natural environment, which includes the air, coasts, water, land and biodiversity and the ecosystem services they provide.
The earthquake did not significantly impact on biodiversity in the broader regional sense; however considerable impacts on the health of localised aquatic ecosystems occurred and are discussed in the ‘water’ section below. Many of the recovery activities underway in other programme areas may improve the health and resilience of the natural environment to better than pre-quake conditions.
The Natural Environment Recovery Programme has been adopted by Environment Canterbury commissioners and is available on the Environment Canterbury website.
Natural environment recovery goals
Restore the natural environment to support biodiversity and economic prosperity and to reconnect people to the rivers, wetlands and Port Hills by:
- ensuring recovery activities value, protect and sustainably manage the sources of our water;
- ensuring ecosystems are healthy and functioning;
- improving the quality and function of estuaries, waterways and wetlands to support the unique biodiversity that is endemic to Te Waipounamu;
- providing public access to and opportunities for outdoor recreation, cultural, social and economic activities;
- enhancing air quality through managing recovery activities that impact on air quality, such as heating, transport, demolition and construction; and
- storing, sorting and processing waste in an environmentally safe and effective manner, including minimising and recycling construction and demolition wastes.
Environment Canterbury’s draft Long Term Plan is currently being prepared and will include details on earthquake recovery projects. It sets out Environment Canterbury’s goals, work programmes and provides the framework for the levels of service that will be delivered over the next ten years. Work is occurring under the portfolios listed below.
Christchurch has a long-standing air quality problem caused primarily by fine airborne particles from domestic open fires and wood burners. Although thousands of chimneys fell down during the earthquakes, many of these were from open fires banned from use in Christchurch and therefore do not necessarily represent a gain for air quality. The overarching objective for air quality in Canterbury is to meet the National Environmental Standard for Air Quality in 2016.
There is considerable uncertainty around the impact of the earthquakes on air quality in Christchurch. Environment Canterbury will monitor air quality in Christchurch and Kaiapoi over the next 2-4 years to update air quality projections and understand how the earthquakes have affected air quality. Enforcement of the air plan rules remains sensitive towards those in earthquake-affected circumstances.
A key focus for the hazards section of the Natural Environment Recovery Programme is providing up-to-date and easy-to-understand earthquake, tsunami and landslide science information. Up-to-date information on hazards is important for the community and organisations, such as councils and infrastructure providers, to make informed decisions about risk reduction, readiness, response and recovery.
Research is helping to review and expand the knowledge base and maps for liquefaction hazards, assess damage and risk from rockfalls in the Port Hills, landslide hazards, tsunami inundation areas, and earthquake fault information. Research outcomes will be published on the Environment Canterbury website as they become available.
Stopbanks (for protection from flood hazards) were also damaged by the earthquakes and are being repaired in order of priority.
The Avon Heathcote Estuary/Ihutai has been impacted by the earthquakes as a result of topographical changes, large areas of liquefaction throughout the estuary, and from contamination by raw waste water that was being pumped into the Avon/Ōtākaro and Heathcote/Ōpāwaho rivers and the estuary itself. Pre-existing biota has been buried by liquefaction sediments, and/or redistributed by the topographical changes. Shellfish were contaminated.
Research undertaken to determine the impacts of the earthquakes on the Avon Heathcote Estuary/Ihutai included:
- testing of estuary shellfish
- an assessment of the height of the estuary seabed
- surveys of the estuary habitat and ecosystems
- water quality testing for recreation
Water quality for recreation was also significantly compromised by the discharge of raw sewage into the rivers and estuary following the earthquakes. However, the water quality at most recreational swimming beaches around Christchurch has returned to pre-earthquake conditions.
Inert material from demolition sites is being used to reclaim land in Lyttelton Harbour by the Lyttelton Port Company. Monitoring of the reclamation process is ongoing to ensure harbour water quality and amenity values are maintained.
Much of the Christchurch and Ellesmere coastal control benchmark system, used for state of the environment coastal profile surveying, was damaged by the earthquakes. A large number of these benchmarks need to be re-levelled and reinstated.
Water and waterways
In the Avon/Ōtākaro, Heathcote/Ōpāwaho, and Styx/Pūrākaunui rivers silt has smothered the habitat of the plants and animals that lived in these small waterways. The lower reaches of these rivers have been affected by sewage contamination, liquefaction, sediment input from stormwater, as well as changes to bed levels and riverbanks. This has affected aquatic ecosystem health and altered flooding levels at high tide.
Environment Canterbury and Christchurch City Council are working closely together to assess the effects the earthquakes have had on infrastructure and waterways around the city. This is to ensure that pragmatic decisions to enable repair and rebuilding (via the SCIRT programme of works) occur as efficiently as possible, while trying to avoid further adverse effects and improve and restore the health of waterways, where possible. Bank stabilisation, repair of waterway structures, dredging of riverbeds and realignment of waterways is necessary in some areas.
To determine the impact of the earthquakes on the water quality and ecosystem health of our rivers, research undertaken included:
- river water quality modelling
- surveys of river fish, invertebrates and fish spawning
- water quality testing for recreation
Reports completed to date are available. The reports include recommendations for actions that could be taken to aid the recovery of aquatic ecosystems and these will be considered as part of the Natural Environment Recovery Programme.
There have been no real delays to the progress of the Canterbury Water Management Strategy (CWMS). The Christchurch-West Melton Zone Committee will make recommendations about management of red zone land and earthquake recovery to meet CWMS targets in their forthcoming implementation programme.
An estimated 8 million tonnes of construction and demolition waste will be generated by the earthquakes. Industry and Councils are working together to find new solutions for recycling or reusing earthquake waste. Waste management solutions need to balance environmental concerns, maximisation of efficiencies, rapid and affordable recovery and the appropriate management of sensitive waste.
Earthquake waste is being transported to a combination of new and pre-existing facilities that are authorised to store, sort, process or dispose of wastes.
Environment Canterbury is collaborating with strategic partners on potential hazardous substances, resolving waste management issues and contaminated land risks during the demolition process. A grant from Government’s Waste Minimisation Fund will assist the collection and disposal of hazardous wastes from the residential demolition process.
Environment Canterbury is leading the Natural Environment recovery programme in partnership with Te Rūnanga o Ngāi Tahu, Christchurch City Council, Selwyn District Council, Waimakariri District Council and CERA, using existing mandates and policies.
The programme also relies on collaboration with a number of other agencies and organisations, including the Canterbury District Health Board, central government departments, civil defence, research institutions and community groups.