Definitions of key terms used throughout our facts, stats and figures.

Accidental or unintentional injuries Unintentional is used to refer to injuries that were unplanned. Unintentional injuries can be defined as events in which:
The injury occurs in a short period of time – seconds or minutes,
  • The harmful outcome was not sought, or
  • The outcome was the result of one of the forms of physical energy in the environment or normal body functions being blocked by external means, e.g., drowning.
The most common unintentional injuries result from motor vehicle crashes, falls, fires and burns, drowning, poisonings and aspirations
Accommodation unit (Stay unit)

Unit of accommodation that is available to be charged out to guests (such as a room in a hotel or motel, a bed in a backpacker establishment, or a site in a caravan park). More information about the Accommodation Survey from Statistics New Zealand(external link).

Active modes of transport

Journeys made by physically active means, such as cycling, walking, jogging and scootering.

Age-Sex structure

A younger population typically has a higher proportion of younger people (the base of the pyramid) and a progressively smaller proportion of older people (the peak of the pyramid).

An ageing population is typically represented by more of a rectangle shape, which has a bulge in the middle of the pyramid and a high proportion of older people at the top.


Airbnb is short for air bed and breakfast. It is facilitated via the Airbnb website, which connects people (normally travellers) looking for accommodation with hosts advertising available accommodation (either within their own homes or entire homes/apartments that they manage). More information from Airbnb(external link).

Airbnb active listings

ChristchurchNZ receives monthly Airbnb data sourced by AirDNA. AirDNA only reports on “active” properties.

A large percentage of listings on Airbnb are no longer being actively rented, haven’t updated their calendar in many months, or haven’t accepted a reservation for an extended period of time.

AirDNA removes these listings from their analysis to provide a more accurate picture of the current competing properties in each area. This means that the number of listings published on this website may differ to the number of listings published elsewhere. More information from AirDNA(external link).

ANZSIC industrial classifications

The Australian and New Zealand Standard Industrial Classification (ANZSIC) 2006 is used to compile and analyse industry statistics in New Zealand and Australia. 

ANZSIC06 has a structure comprising categories at four levels, namely divisions (the broadest level), subdivisions, groups, and classes. More information from Statistics New Zealand(external link).

Area unit

Non-administrative geographic areas created by Statistics New Zealand and roughly relate to suburbs. In Christchurch City, there are 129 area units. 

Average household size

The mean number of people per household. It is calculated by dividing the number of people in households by the number of households. 

Avon Heathcote Estuary /Ihutai Water Quality Index In 2014 ECAN started using an index to rate water quality sites from Very Poor to Very Good based on the Canadian Council of Ministers for the Environment(CCME) water quality index.  More information about this index can be found on page 4 of the Healthy Estuary and Rivers of Christchurch - Water quality of the Estuary of the Heathcote and Avon  Rivers / Ihutai report 2016.(external link)
Brownfield site Area of previously developed land that is generally vacant or derelict. They are often former commercial or industrial sites which may or may not be contaminated.
Building consents

May be for detached, semi-detached or attached dwellings and units. The majority of building consents that are issued are completed, however, there is a small proportion of consents that are issued but not constructed.

Business birth

Birth occurs when a new enterprise starts operation (i.e. a combination of production factors is created, and no other national businesses are involved). Births do not include entries into the population due to reactivations, mergers, break-ups, split-offs, or another restructuring of a group of businesses linked by ownership or control. More information from Statistics New Zealand.(external link)

Business turnover

This indicator is considered a reliable measure of business activity. Business turnover is defined as the sum of business start-ups and closures. Business start-ups as a share of business turnover are used as a proxy measure for gauging the level of entrepreneurial activity in the economy.

CCC General Service Satisfaction survey (Residents survey)

For general activities that most or all residents in the city use, such as water supply, waste collection and road surfaces, a representative random sample of all city residents over the age of 15 is used to measure resident satisfaction.

Central City Business Survey

The Central City Business survey was commissioned by the Christchurch City Council to gauge business owner's views about aspects of the central city in Christchurch.

Central City or Four Avenues

Incorporates the three area units (Cathedral Square, Hagley Park and Avon Loop) bounded by Deans Avenue, Harper/Bealey Avenues, Fitzgerald Avenue and Moorhouse Avenue.

Child: Older person ratio

A measure of the composition of the portion of the population that is made up of dependents, those who are typically too young and those who are typically too old to work.

This is expressed as the number of children aged 0 to 14 years, divided by the number of those aged 65 years and over. A decreasing Child:Older person ratio illustrates a shift in the type of dependents, from more children to more older people.

Christchurch Visitor Experience survey

This survey is run annually by ChristchurchNZ to better understand visitor experience in Christchurch, including what activities visitors do and their satisfaction with aspects of the city's tourism.

Visitors are approached during the peak summer period and given the option to complete a 10-minute survey immediately (on an iPad), or be sent an invitation by email to complete an online version later. Field staff were located at key visitor sites including the i-SITE visitor information centre, the airport, Cashel Mall, and Cathedral Square. More information from ChristchurchNZ(external link).

ChristchurchNZ RTO (Regional Tourism Organisation)

ChristchurchNZ is the city’s economic development and city profile agency and is the Regional Tourism Organisation for the Canterbury Region (includes Christchurch City, Selwyn, Waimakariri, Ashburton and Hurunui Districts).

ChristchurchNZ is responsible for promoting Christchurch and Canterbury as a tourism destination to media, travel trade, conventions and directly to visitors. More information from ChristchurchNZ(external link).

Commercial floorspace

New floorspace is extracted from commercial building consents issued for new buildings and additions to existing buildings. The majority of building consents that are issued are completed, however, there is a small proportion of consents that are not completed.

It is assumed the general floorspace trends shown in this measure are not significantly affected by these uncompleted consents. This data is based on floorspace estimations and development plans registered with Christchurch City Council building consent applications; the planned floorspace may differ to the 'as-built' figures.

Commercial property investor confidence

Colliers’ quarterly confidence survey asks commercial property market participants about their views on the outlook for commercial property investment over the next 12 months.

Overall net confidence is calculated (% of optimists minus pessimists). More information from Colliers.(external link)

Condition of the natural environment

The Life in Christchurch survey asks respondents to indicate which natural environments they believe to be in good or poor condition.

A natural environment in good condition will be resilient, support natural habitats and biodiversity, as well as supporting human health and well-being.

A natural environment in poor condition will be vulnerable, unable to support natural habitats and biodiversity, as well as a risk to human health and well-being.

Cordon (central city)

Following the February 2011 earthquake, the central city was placed under an army and police cordon due to unsafe buildings and public spaces, and ongoing earthquake activity. It initially covered 387 hectares.

It gradually reduced in size as streets became safe for the public to access, and was finally lifted in June 2013.

Couple with Child(ren) family type

A couple with child(ren), all of whom have usual residence together in the same household. The children do not have a partner or child(ren) of their own living in the household. More information from Statistics New Zealand.(external link)

Couple without Children family type

A couple without child(ren), with or without other people, usually living together in a household. More information from Statistics New Zealand.(external link)

Dependency ratio

A measure of the balance between dependents (those who are typically too young or too old to work) and those of working age in the city's population.

The ratio is expressed as the combined number of people aged 0 to 14 years and people aged 65 years and over (‘non-working age’ population), divided by those aged 15 to 64 years (the ‘working age’ population).

A rising dependency ratio illustrates an increasing imbalance in the size of the non-working population dependents) versus the working population, and gives an indication of the burden on those of working age to provide for those who are typically not of working age (although people are increasingly working into older ages). 


The New Zealand Deprivation Index reflects aspects of social and material deprivation, based on a combination of the following census data: income, employment, qualifications, owned home, support, living space, transport and communication.

The scale reflects a continuum from 'least deprivation' (decile 1) to 'most deprivation' (decile 10). More information from the University of Otago(external link).

Drinking-Water Standards

Drinking water suppliers must take all practicable steps to meet the Drinking-Water Standards for New Zealand 2005 (Revised 2008) (the Standards). The sStandards have three main components:

  • the water quality standards, which specify the maximum acceptable values (MAVs) of a range of microbiological, chemical and radiological properties of drinking-water (determinands). The MAVs are set at a level below which there is no significant risk to a consumer over a lifetime of drinking-water consumption

  • the compliance criteria and reporting requirements, which define the checks needed to demonstrate a drinking-water supply is not exceeding the drinking-water quality standards. The stringency of these checks reflects the level of risk that the drinking-water supply poses

  • the remedial actions, which a supplier must take in the event of a transgression. A transgression occurs when the MAV or some operational requirement of the drinking-water supply is exceeded.

More information is available in the annual report on drinking water quality (external link)

Dwelling units

Refers to new dwellings that have been consented for, generally intended for one household. The consent may be classified as for a separate dwelling or for an attached unit (e.g. apartment, terraced housing, joined townhouse etc.).

Earthquake Commission (EQC)

EQC provides natural disaster insurance for residential homes, land and contents. Those with private insurance policies that include fire insurance are automatically covered.

Buildings are generally insured up to a maximum of $100,000+GST (minus excess). Private insurers make decisions on claims greater than this amount. More information from EQC.(external link)

Employed population Refers to the population aged 15 years and over, and includes full-time and part-time employed. More information from Statistics New Zealand(external link).
Estimated resident population

The estimated resident population of an area in New Zealand at a given date after census night.

It is derived by updating the census usually resident population count for; estimated net census undercount; the estimated number of residents temporarily overseas on census night; natural increase (births less deaths) between census night and the given date; net migration (arrivals less departures) between census night and the given date. More information from Statistics New Zealand(external link).


Ethnicity is the ethnic group or groups that people identify with or feel they belong to. Ethnicity is a measure of cultural affiliation, as opposed to race, ancestry, nationality or citizenship. Ethnicity is self-perceived and people can belong to more than one ethnic group. More information from Statistics New Zealand(external link).

'European or Other' ethnic group

For the purposes of ethnic population projections, Statistics New Zealand group those people who belong to the European or Other (including New Zealander) ethnic groups defined in Level One of the ethnicity classification.

If a person belongs to both the European and Other ethnic groups, they have only been counted once. Almost all people in the Other ethnicity group belong to the New Zealander subgroup. More information from Statistics New Zealand(external link).


A household containing two or more people usually living together, with at least one couple and/or parent-child relationship, with or without other people.

Couple-without-children families include

(a) couples who will never have children,

(b) couples who will have children in the future, and

(c) couples whose children have left the parental home.


New business floorspace refers to building consents issued for new buildings and additions to existing buildings, within specified business zones.

New Zealand General Social Survey (Well-being statistics)

The New Zealand General Social Survey(external link) (NZGSS) provides information on the well-being of New Zealanders aged 15 years and over. It covers a wide range of social and economic outcomes and shows how people are faring.

In particular, the survey provides a view of how well-being outcomes are distributed across different groups within the New Zealand population. The survey contributes to Well-being statistics.

Global Financial Crisis (GFC)

The financial crisis of 2007–2008, also known as the global financial crisis and the 2008 financial crisis, is considered by many economists to have been the worst financial crisis(external link) since the Great Depression(external link) of the 1930s. More information.(external link)

Greater Christchurch

Refers to the urban area of Christchurch City and Lyttelton Harbour, as well as the 'commuter belt' communities in Selwyn and Waimakariri Districts. More information from the Greater Christchurch Partnership(external link)

Greenfield area or site

Area of previously undeveloped land used for agriculture, landscape design, or left vacant, which has been identified as being suitable for development. Generally located on the outskirts of an urban area.

Gross domestic product (GDP)

New Zealand's official measure of economic activity and growth. It is the measure of the value-added from all economic activity in New Zealand. The figures below are expressed in nominal terms (not adjusted for inflation).

It is an important tool that helps a range of data users, including policymakers, understand and manage the New Zealand economy. Regional gross domestic product (GDP) is a geographic breakdown of national-level GDP. More information about Gross Domestic Product from Statistics New Zealand(external link).

Ground Floor Activity survey

The purpose of this survey is to measure the nature of the pedestrian environment in the central city commercial areas. This provides a view of how the pedestrian environment is changing and where different activities are located, and how these have changed over time.

The survey has been going since 2001, with a break between 2011 and 2015 as a result of the Canterbury Earthquake Sequence in 2010 and 2011.

Guest night

Equivalent to one guest spending one night at an establishment. For example, a motel with 15 guests spending two nights would report a provision of 30 guest nights of accommodation. More information about the Accommodation Survey from Statistics New Zealand(external link).

Health Act 1956

This requires water suppliers to meet the following requirements:

  •  Water safety plans: Every drinking-water supplier, with the exception of small suppliers, must implement an approved water safety plan for their drinking-water supplies. The supplier must review its water safety plan within five years of approval.
  • Compliance with the drinking-water standards: Every drinking-water supplier has a duty to take all practicable steps to ensure that the drinking-water it supplies complies with the Standards.
  • Provision of drinking-water: Every drinking-water supplier must take all practicable steps to ensure it provides an adequate supply of drinking water to each point of supply. Interruptions may occur for planned maintenance, for improvements or for emergency repairs. However, if the interruptions are likely to exceed eight hours, the supplier must have prior approval from the medical officer of health and must have taken all practicable steps to warn affected people. If the supply is interrupted in an emergency, the supplier has up to 24 hours to inform the medical officer of health.
  • Source protection: Every drinking-water supplier must take reasonable steps to protect their water sources from contamination and pollution. These steps may include making submissions on district plans, resource consent applications or sanitary service assessments. They may also include contributing to catchment management.
  • Monitoring: Every drinking-water supplier must monitor the drinking-water it supplies, to check whether it meets the Standards, or presents a public health risk.
  • Record-keeping: Every drinking-water supplier, with the exception of small suppliers, must keep records of its drinking-water supplies, containing sufficient information to enable a drinking-water assessor to ascertain whether the supplier is meeting the requirements of the Act.
  • Complaints: Every drinking-water supplier must record and investigate complaints about its supply.
  • Remedial actions: Every drinking-water supplier must take appropriate remedial action to correct problems if its supply does not meet the Standards. 
More information is available in the annual report on drinking water quality (external link)

A household can be a person living alone, one or more families, or related/unrelated individuals, all sharing the same usual residence and sharing facilities (for example, eating facilities, cooking facilities, bathroom and toilet facilities, a living area), in a private dwelling.

Household crowding

There is no standard measure of crowding used internationally, but in New Zealand, the Canadian National Occupancy Standard (CNOS) is often used as a de-facto standard. 

A household is said to be crowded if the dwelling requires extra bedrooms according to criteria which relates to the relationship of occupants to one another, and the age and sex of any children within the household. More information from Statistics New Zealand(external link).

Household energy costs

The Household Economic Survey categorises energy costs as including electricity, gas (reticulated and bottled), solid fuels (coal and firewood), liquid and domestic fuels (oil and kerosene), as well as service provider costs (bonds, connections, service fees etc).

Household emergency plan A household emergency plan is an agreed plan that enables a household to look after household members for at least 3 days or more.  More information on the get thru website(external link)
Household expenditure

The Household Economic Survey runs every three years and respondents are asked to record everything the household spent money on in the previous two weeks.

Total net expenditure refers to the net of refunds, sales, and trade-ins. All group and subgroup level expenditure is reported as a gross expenditure.

Category expenditure is defined using the New Zealand Household Expenditure Classification (NZHEC). All expenditure at group, subgroup and class level is reported as a gross expenditure. All expenditure includes GST. More information from Statistics New Zealand.(external link)

Household income inequality

Household income inequality as measured by the ratio of the income in the second-highest decile (P80) to the income in the second-lowest decile (P20).

The P80:P20 ratio gives a reasonable indication of the degree of dispersion for the range within which the majority (60%) of the population fall and has less volatility than the P90/P10 ratio. More information from Statistics New Zealand(external link).

Household private transport supplies and services costs

The Household Economic Survey categorises energy costs as including vehicle parts and accessories, petrol, other fuels/lubricants, servicing and repairs, and other private transport services (e.g. registration and licensing, WOF, road user charges, parking fees, toll charges, drivers license fees etc).


Total personal income received is the before-tax income of a person aged 15 years or over in the 12 months ended 31 March 2013. The information is collected as income bands rather than in actual dollars.

Total personal income can be combined with other income information from the same family or household to provide a range of measures (e.g. total household income). More information from Statistics New Zealand(external link).

Infill site Infill sites are located in existing residentially developed areas and may include sites where the existing building is demolished and replaced with more than one unit, or the existing site is subdivided or cross leased.

The consumer's price index (CPI) provides information about changes to the prices of consumer items New Zealand households buy and provides the most commonly used and recognised measure of inflation in New Zealand. More information from Statistics New Zealand(external link) and Reserve Bank of New Zealand's 'Inflation Calculator'(external link).

(external link)Inflation-adjusted income

The data is adjusted to reflect incomes as they would have been in June 2006, to remove the effects of inflation and allow for comparisons over time. Income applies to the population aged 15 years and over.

Languages spoken

Language(s) in which the respondent could have a conversation about a lot of everyday things.

Life expectancy

A summary measure of the death and survival rates of the population. The average length of life of a newborn baby, assuming they experience the age-specific mortality rates of that year throughout their life.

Life in Christchurch survey

Life in Christchurch is an annual survey series that asks residents for feedback on a variety of key aspects related to life in Christchurch. Topics include transport, the central city, natural environment, and neighbourhood and communities.

It is a web-based survey, which uses a 'snowball' method to reach respondents, using a word-of-mouth approach. This has the advantage of reaching specific groups and those who may not usually provide feedback to the Council. It is not necessarily representative of the wider community, however, feedback is provided by thousands of willing residents. More information about Life in Christchurch.

Longitudinal Business Frame

The Business Frame has been designed by Statistics New Zealand(external link), to primarily provide current, point-in-time snapshots of business populations, as well as longitudinal business data that follows the same units over time, providing information about long term trends.

Mean annual low flow (MALF)

This describes how low the flow gets in a typical year. The lowest flow for each year is averaged across recorded years to estimate the mean annual low flow. To avoid splitting a single drought event across years, a water year (July to June) is used instead of a calendar year (Jan-Dec). Definition from LAWA website(external link).

Median age

Half the population is younger, and half older, than this age.

Median income

Half earn more than, and half less than this figure.


Middle Eastern/Latin American/African.

Meshblock The smallest geographic unit created by Statistics New Zealand for statistical data collection and processing. They are generally the size of a street block in urban areas and can be aggregated to form area unitsIn Christchurch City, there are approximately 3500 meshblocks.
Metals (particularly copper, lead and zinc)

Metals, in particular, copper, lead and zinc, can be toxic to aquatic organisms, negatively affecting fecundity, maturation, respiration, physical structure and behaviour. The toxicity of metals in freshwater, and therefore the risk of adverse biological effects, alters depending on the hardness, pH and alkalinity of the water.

Metropolitan part of the city The area of Christchurch City prior to the 2006 amalgamation with Banks Peninsula District.
Natural increase

Births minus deaths. Negative values denote natural decrease.

NEET rate

Young people aged 15–24 years who are unemployed (part of the labour force) and not engaged in education or training, and those not in the labour force, and not engaged in education or training due to multiple reasons. NEET = not in employment, education or training. More information from Statistics New Zealand(external link).

Net internal migration

Internal migration refers to the movement of people into and out of Christchurch from other parts of New Zealand. Net internal migration (calculated as arrivals minus departures) is a component of population growth. More information from Statistics New Zealand(external link).

Net external migration

External migration refers to the movement of people into and out of Christchurch City from overseas. Net external migration (calculated as arrivals minus departures) is a component of population growth. More information from Statistics New Zealand(external link).

Net migration

Net migration is expressed as a positive or negative figure and is derived by subtracting departures from arrivals.

A positive net migration figure occurs when more people arrive in Christchurch than depart. A negative net migration figure occurs when there are more departures from Christchurch than arrivals.

Net new housing

Net new housing refers to gross new housing minus any demolitions/rebuilds (i.e. it excludes replacement housing where demolition has occurred).

It is an indicator of what is being added to the city’s housing stock rather than replaced. The gross figure of new housing units will contain a number of replacement housing units where demolitions have occurred.

Notifiable diseases

Health practitioners are required by Section 74 of the Health Act 1956(external link) to report to the medical officer of health any patient they have 'reasonable suspicion' is suffering from a notifiable disease. Notification allows for appropriate public health control measures to be taken to reduce the risk of further spread, for disease surveillance and for monitoring of the effectiveness of control measures. More information from the Ministry of Health.(external link)   Canterbury DHB reports on trends in notifiable diseases quarterly through their Public Health Surveillance and Incident Intelligence website(external link).

Christchurch City reports on food and water-borne diseases that are likely to be the result of local activities rather than from overseas travel.  These include campylobacteriosis, cryptosporidiosis, giardiasis, salmonellosis and yersiniosis.

Campylobacteriosis - Cryptosporidiosis is a gastrointestinal illness caused by the protozoa Cryptosporidium of which there are at least 15 species.  The most common symptom of cryptosporidiosis is watery diarrhoea.  Other symptoms include stomach pain, nausea, vomiting, fever and weight loss. Symptoms usually last about 1 to 2 weeks in persons with healthy immune systems.

Yersiniosis - In children under 5 years old, Yersinia enterocolitica infection typically causes diarrhoea, vomiting, fever and occasionally abdominal pain. In contrast, older children and adults are more likely to experience abdominal pain as the prominent symptom.

The Canterbury DHB Public Health Surveillance and Incident Intelligence website(external link) have more detailed information on both Yersiniosis and Campylobacteriosis.

Occupied Dwelling

For census use, a dwelling is defined as occupied if it is: occupied at midnight on the night of census data collection, or occupied at any time during the 12 hours following midnight on the night of census data collection unless the occupant(s) completed a questionnaire at another dwelling during this period. This includes occupied dilapidated dwellings and occupied dwellings under construction. More information from Statistics New Zealand(external link).

Occupied Non-Private Dwelling

Occupied non-private dwellings provide short or long-term communal or transitory type accommodation. They are generally available to the public for reasons of employment, study, special need, legal requirement, or recreation.

They include guest accommodation (e.g. hotels, youth hostels etc.), communal living (e.g. camps, hospitals, institutional complexes etc) and facilities for paying guests (e.g. home stays, farm stays etc.). More information from Statistics New Zealand(external link).

Occupied Private Dwelling

An occupied private dwelling accommodates a person or group of people and is not generally available for public use. The main purpose of a private dwelling is as a place of habitation; it is usually built (or converted) to function as a self-contained housing unit. More information from Statistics New Zealand(external link).

One Parent family type

One parent with child(ren), with or without other people, usually living together in a household.

Other multi-person households

A household containing two or more people usually living together, but not as a couple or parent-child relationships with each other.

Pedestrian Activity survey An observation study of pedestrians at key sites in the Central City, over two-hourly periods throughout the day and on different days of the week.
Physical activity

The Quality of Life Survey asks respondents how many days in the previous seven days they had been physically active.

For the purpose of this survey, ‘active’ was defined as 15 minutes or more of vigorous activity (an activity which made it a lot harder to breathe than normal), or 30+ minutes of moderate exercise (e.g. an activity that makes you breathe harder than normal, such as brisk walking).

Population density

The number of usual residents in a standardised area (per square hectare), and reflects the concentration of population. Density is influenced by land zoning, housing type and household composition.

Population, household and family projections

Statistics New Zealand produces projections based on assumptions about future fertility, mortality and migration. Three projections (low, medium, and high growth) incorporating different fertility, mortality, and migration assumptions for each geographic area have been produced to illustrate a range of possible scenarios.

At the time of release, Statistics NZ considers the medium projection suitable for assessing future population, family and household changes. Projections are not predictions. The projections should be used as an indication of the overall trend, rather than as exact forecasts. More information from Statistics New Zealand(external link).

Potential sections

This is the total number of sections that the particular development is likely to yield once the whole development of the area is complete. The availability type can be further defined by:

  • Sections with subdivision consent (number of sections within a development for which the Council has granted subdivision consent- may only apply to part of a development)
  • Sections sold with subdivision consent (this information comes from the developer or their agent, and reflects the sales they have made)
  • Sections for sale with subdivision consent (assumes sections are for sale as soon as they have received subdivision consent from the Council)
  • Sections with titles (number of sections with subdivision consent which have also been issued a Title by Land and Information New Zealand).
(external link)Qualification

A qualification is a formally recognised award for educational or training attainment, where formal recognition means that the qualification is approved by a specified authority. More information from Statistics New Zealand(external link).

Quality of Life survey

A collaborative project between seven city councils and two regional councils, covering 65% of the country's population. The methodology changed between 2010 and 2012, from a telephone survey to a mailed out invitation, requesting respondents self-complete the survey online or via hard copy.

The age of eligibility increased from 15 years to 18 years. These changes in methodology have had an impact on the times series, meaning results from 2012 onwards cannot be compared directly with the results from previous measures. More information from Quality of Life(external link).

Quantitative Macroinvertebrate Community index (QMCI)

The QMCI is a set of biotic indices used to monitor and report on the health of New Zealand streams.  These indices were created by the Ministry for the Environment and are used by the Christchurch City Council, in conjunction with Environment Canterbury and Avon-Heathcote Estuary Ihutari Trust.  More information from the Ministry for the Environment(external link).

Reports of concern to Oranga Tamariki (Ministry of Children)

Any person who believes that any child or young person has been, or is likely to be, harmed, ill-treated, abused, neglected or deprived may report the matter to Oranga Tamariki - Ministry of Children(external link) or the NZ Police. These are referred to as reports of concern.

Reports of concern made to Oranga Tamariki are assessed for urgency and are followed up to assess whether further action is required and whether there is evidence of substantiated harm.

Until 2017, the Ministry of Social Development(external link) reported notifications including 'reports of concern' and Police family violence referrals, where Police attended a family violence incident (where children were present or normally resident at the household) and Police decided that further action was not required. From 2018 onward, Oranga Tamariki does not include Police family violence referrals in their 'reports of concern' data. More information from Oranga Tamariki(external link).

Residential red zone

Post-earthquakes, areas in the flat land residential red zone which have area-wide land and infrastructure damage, and an engineering solution to repair the land would be uncertain, costly, and is likely to be highly disruptive.

Areas in the Port Hills which are affected by cliff collapse and/or rockfall where there is an unacceptable risk to life and cannot be easily remediated or mitigated. More information from Land Information New Zealand(external link).

Religious affiliation

Religious affiliation is a self–identified association of a person with a religion, denomination or sub–denominational religious group. Religion is a set of beliefs and practices, usually involving acknowledgement of a divine or higher being or power, by which people order the conduct of their lives both practically and in a moral sense. 

All religious affiliation questions contain an option allowing people to object to answering the question. This needs to be taken into account when interpreting religious affiliation data. More information from Statistics New Zealand(external link).

Replacement housing (rebuilds)

Replacement housing refers to residential construction which replaces a single dwelling that was already within the existing housing stock.

For example, if a single dwelling is demolished and replaced with a single dwelling, there is no net gain to the City's housing stock. It is a simple rebuild and is classed as replacement housing.

However, if a single dwelling is demolished and replaced with two dwellings (such as townhouses), then the net new housing gain would be one dwelling.


This reflects is where zoning is changed in the Christchurch District Plan(external link) through a formal process.

SA1 (Statistical Area 1)

The main purpose of the SA1 geography is to provide output geography that allows the release of more low-level data than is available at the meshblock level.

Built by joining meshblocks, SA1s have an ideal size range of 100–200 residents, and a maximum population of about 500. This is to minimise suppression of population data in multivariate statistics tables. More information from Statistics New Zealand(external link).

SA2 (Statistical Area 2)

The main purpose of the SA2 geography is to provide output geography for higher aggregations of population data than can be provided at the SA1 level.

The SA2 geography aims to reflect communities that interact together socially and economically. In major urban areas, an SA2 or a group of SA2s often approximates a single suburb. SA2s in city council areas generally have a population of 2,000–4,000 residents. More information from Statistics New Zealand(external link).

Social cost of road crashes and injuries

The social cost estimates include all costs (including non-financial cost) incurred as a result of a crash/injury, irrespective when the cost incurs and who pays. The total social cost estimates are based on accident year and include the estimated cost of loss of life and life quality, loss of output, medical cost, property damage costs and legal and court costs. All on-going costs are incorporated in the social cost estimates. In other words, the social cost estimates is a measure of the true costs of road crashes and injuries. More information from the Ministry of Transport.(external link)

Sources of Income

Identifies the various sources from which an individual aged 15 years and over received income in the 12 months ending 5 March 2013. More information from Statistics New Zealand(external link).

Stationary Activity survey

Records and maps what people are doing within a space at a given time, such as sitting on a bench, playing sports, or performing live music. The result is a “snapshot” of activity in a particular public space. More information at Gehl Institute.(external link)

Stay unit nights available A basic measure of an establishment's accommodation capacity. It is defined as one stay unit multiplied by one night. For example, 10 units in a motel available for guest use (whether occupied or not) for the full 31 days in July would have an accommodation capacity of 310 stay unit nights.
Study participation

Measures those attending, studying, or enrolled at school or anywhere else. It is grouped into full-time study (20 hours or more a week), part-time study (less than 20 hours a week), and those not studying. More information from Statistics New Zealand(external link).

Surrounding districts

Refers to Waimakariri and Selwyn Districts.

Trophic Level indicator (TLI)

The higher TLI scores mean poorer water quality, due to higher nutrients and fertility of the water which encourages growth, including algal blooms.

Four parameters are measured: water clarity, chlorophyll content, total phosphorus and total nitrogen. From these parameters, a TLI value is calculated. In cases where water clarity data is missing a three-parameter TLI is calculated.   View a factsheet on TLI(external link) one the LAWA website.

Two Parent family type

A couple with child(ren), with or without other people, usually living together in a household.

UK (Not further defined)

This category captures migrants who specified 'United Kingdom' on their arrivals card as the country of last residence, without specifying which country (e.g. England, Wales, Scotland or Northern Ireland- which each have their own category).

Unoccupied private dwelling

For census use a private dwelling (i.e. place of habitation not generally available for private use) is defined as unoccupied if it is unoccupied at midnight and at all times during the next 12 hours following midnight on the night of the data collection. Unoccupied dwellings may be classified as 'empty' or 'residents away'. More information from Statistics New Zealand(external link).

Urban Development Strategy

Developed in 2006, a partnership involving Christchurch City, Waimakariri District and Selwyn District (along with Ecan and NZTA) focusing on long-term growth in the built-up areas of Greater Christchurch area. The UDS area excludes most of Banks Peninsula and the western parts of the Waimakariri and Selwyn Districts.  In June 2017 the name was changed to Greater Christchurch Partnership(external link) to reflect its expanded membership and a broader range of responsibilities post earthquakes.

Vacant land

Vacant land, zoned for residential, commercial or industrial purposes, is defined in the District Plan as undeveloped areas on which potential future development is allowed. The area of land considered vacant by a set of thresholds is measured and recorded in a vacant land summary register.

A land parcel may be registered vacant in greenfield areas if it is rezoned from rural to urban purposes, or in infill areas if a utilised parcel is subdivided producing a vacant site, or existing buildings on a developed site are demolished to enable redevelopment.

Land classed as vacant in the register does not necessarily mean unused land: it may be used for commercial activity (industrial yards with no buildings), contain a swimming pool, tennis court, or even small ancillary buildings.

Notes: The vacant land register is a long-term strategic planning aid, designed to give an outlook for strategic zoning decisions; it should be assessed with this in mind – it is the overall trend in the residual land capacity that is derived from this data, not site-specific development characteristics. The residential red zone is excluded from vacant land summary figures.

Versatile soils

The Horticultural Versatility System has been used to assess the extent of high productivity soils in Christchurch City.

Versatility is mainly assessed in terms of the soil's physical characteristics and assumes that nutrient and soil moisture limitations are overcome by fertiliser application and irrigation. Soils in Christchurch generally relate to the local topography.


‘Victimisations’ count each instance of a person, organisation or premises being victimised for one or more offences; the ‘unique victims’ population only counts each victim once irrespective of how many times they have been victimised during the reference period. More information from NZ Police(external link).

Voter turnout

At the local government level, ‘Turnout’ is the percentage of electors (for those areas where an election was necessary) who voted. ‘Overall turnout’ is the total number of residential and ratepayer voters (including those who cast informal, blank and valid special votes) divided by the total number of electors on both the residential and ratepayer rolls in contested areas. More information from the Department of Internal Affairs(external link).

At the general elections, voter turnout is the number of voters as a percentage of enrolled electors. More information from the Electoral Commission(external link).


A wananga is characterised by teaching and research that maintains, advances, and disseminates knowledge and develops intellectual independence, and assists the application of knowledge regarding ahuatanga Maori (Maori tradition) according to tikanga Maori (Maori custom). There are currently three wananga recognised under section 162 of the Education Act 1989.

Water Quality Index

A Water Quality Index (WQI) was developed for the CCC monthly monitoring sites, based on a Canadian WQI (CCME; Canadian Council of Ministers for the Environment, 2001(external link)). This index uses three factors to assess water quality: scope (the percentage of parameters not meeting the guideline on at least one occasion); frequency (the percentage of samples that did not meet the guideline); and amplitude (the amount by which the guideline was not met). The WQI ranges from 0 – 100, with 100 representing high water quality. The user can choose which parameters to include and what guideline levels are appropriate to their system.

The parameters used in the CCC WQI were copper, zinc, pH, TSS, DO, temperature, BOD5, total ammonia, NNN, DRP and E. coli. WQI scores were used to categorise the CCC sites as being ‘very poor’ (0 – 39.9), ‘poor’ (40 – 69.99), ‘fair’ (70 – 79.9), ‘good’ (80 – 89.9) or ‘very good (90 – 100). The categories were selected based on local knowledge of water quality compared to other waterways nationally. These categorise Christchurch City waterways as expected. The WQI index was calculated for every year from 2013, to allow comparisons over time. More information in Surface Water Quality Monitoring Report for Christchurch City Waterways: January – December 2017

Water quality parameters

Total Suspended Solids TSS: Elevated levels of suspended sediment in the water column decrease the clarity of the water and can adversely affect aquatic plants, invertebrates and fish  For example, sediment can affect photosynthesis of plants and therefore primary productivity within streams, interfere with feeding through the smothering of food supply, and can clog suitable habitat for species.

Biochemical Oxygen Demand (BOD5): is an indicator of the amount of biodegradable organic material in the water and the amount of oxygen required by bacteria to break down this material. High BOD5 values are due to plant matter, nitrogen and phosphorus, and indicate the potential for bacteria to deplete oxygen levels in the water.

Total ammonia (ammoniacal nitrogen): is typically a minor component of the nitrogen available for plant growth, but at high levels can have toxic effects on aquatic ecosystems. The toxicity of ammonia varies with pH.

Dissolved Inorganic Nitrogen which is the sum of ammonia, nitrite and nitrate, provides a similar measure of eutrophication risk to Nitrate and Nitrite Nitrogen (NNN). Elevated concentrations of NNN can lead to a proliferation of algae and aquatic plants (i.e. eutrophication) because nitrate and nitrite are oxidised forms of nitrogen that are readily available to plants. Eutrophication occurs at much lower nitrate concentrations than toxicity.

Dissolved Reactive Phosphorus: a soluble form of phosphorus that is readily available for use by plants. Phosphorus is an essential nutrient for plant growth and can limit primary production at low levels, but can cause eutrophication at high levels.

Escherichia coli (E. Coli) is a bacterium that is commonly used as an indicator of faecal contamination in freshwater and therefore health risk from contact recreation.

For more information see Section 2.3 of the latest Surface water quality monitoring report for Christchurch.

Working-age population The working-age population comprises the usually resident population of New Zealand who are aged 15 years and over on census night. More information from Statistics New Zealand(external link).

Zoning is outlined in the District Plan, which sets out the framework for the management of land use and subdivision in the city. Careful and considered zoning provides a framework for land use, balancing residential, commercial, industrial, agricultural, environmental and cultural needs. It can encourage or limit areas of urban growth, influencing the existing and future urban form of the city. More information from Christchurch City Council.(external link)

How to use Tableau dashboards

Tableau dashboards have been set up to be customised by the user, by selecting information that the user is interested in. Data can only be viewed, not edited by the user.

Dashboards may contain a combination of maps, charts, tables, and filters. Note some dashboards have multiple tabs.

Hovering over a chart or map with the mouse will usually show some of the underlying data.

Using tabs:

Some dashboards include multiple tabs containing additional information and/or explanations about the data used in the dashboard. These tabs are located at the top of the dashboards.

Using filters:

Most dashboards include filters for geographic areas and for different years but may also have different category filters (e.g. by age group).

When one or more filters are selected, data will generally update in any associated charts or maps for only the selected filters.

Filters can be selected by using drop-down lists, tick boxes, selecting one or more areas on a map, or by selecting one or more series in a chart.

Image of filter

Using maps:

Zoom controls are located in the top left corner of the map. Zoom into maps by using the mouse wheel or by clicking on the 'plus' icon to the left of the map. The 'home' icon will return the map to the original zoom level. 

Image of map control

One or more geographic area (e.g. area unit) can be selected in several ways. Firstly, by clicking on it with the mouse, holding down the mouse and moving it to include other areas. Secondly, by clicking individually on areas and holding down the 'control' key as each area is selected. Thirdly, by using the select tools on the map toolbar to select by radius, rectangle or custom area.

Image of map select

Using charts:

One or more data series can be selected by clicking individually on a series and holding down the 'control' key as each series is selected.

Undoing an action, resetting the dashboard, sharing the dashboard, and downloading data:

These actions can be found in the bottom right corner of the dashboard.

Image of actions

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