Irrigated Land: Data To 2022

What is measured

Irrigated land is an indicator based on data from Stats NZ's Agricultural Production Statistics (APS) programme, which collects data on farms that are registered for goods and services tax (GST) and earn over $60,000 a year.

We report on the total irrigated agricultural land area of farms in Aotearoa New Zealand, as well as by region and by dominant farm type, from the APS census for 2002, 2017, and 2022. We also report on total irrigated land by land use and irrigation system for 2017 and 2022. We approximate the density of irrigated agricultural land nationally in 2022.

Why it is important

Irrigation enables and improves agriculture, by allowing increased agricultural intensity. It can also have adverse consequences that can increase pollution and leaching of contaminants into waterways (Weaver et al., 2015; Wilcock et al., 2011).

An increase in irrigated land leads to more water abstraction and can place increased pressure on river flows, freshwater habitats, mahinga kai, and the wellbeing of taonga species such as tuna (eels), kākahi (freshwater mussels), kōura (freshwater crayfish), and īnanga (whitebait) (Kienzle & Schmidt, 2008; Schallenberg et al., 2013; Williams et al., 2017). These species are important food sources to the people of Aotearoa and are a valued taonga to Māori, embedded within mātauranga and identity.

Irrigation can affect the natural form and character of land (for example, dry land to greener and wetter land), impact recreational fishing, food cultivation and production, drinking water and supply, commercial and industrial water use, and hydro-electric power generation (Cullen et al., 2006; Rankin et al., 2021; Young et al., 2004).

Key findings

The area of irrigated agricultural land in New Zealand almost doubled between 2002 and 2022, from 383,000 hectares to 762,000 hectares (99 percent increase), that is, irrigated land has increased to 5.8 percent of New Zealand's farm area.

Text alternative for Percent of irrigated agricultural land in New Zealand, 2022
A map of New Zealand including the Chatham Islands represents a snapshot of the percent of irrigated agricultural land in New Zealand including Chatham Islands in 2022. The map shows meshblocks and groups of meshblocks coloured one of seven colours from purple to yellow, according to the range in percent of land irrigated, from less than or equal to 3 percent (purple) to greater than 57 percent (yellow). The colour grey represents areas where data is not available.

In 2022:

• Around 84 percent of all irrigated agricultural land was in the South Island.
• Canterbury had the largest amount of irrigated agricultural land (480,000 hectares, 63 percent of New Zealand's total irrigated land area).
• Canterbury had the highest percentage of irrigated agricultural land (19 percent), whereas New Zealand's total irrigated agricultural land was 5.8 percent.

The area of irrigated agricultural land increased in most regions between 2002 and 2022. However, New Zealand's total increase was largely due to the area of irrigated agricultural land in Canterbury doubling (from 241,000 hectares to 480,000 hectares).

In 2022:

• Irrigated agricultural land used for dairy in Canterbury accounted for 70 percent of the New Zealand total for dairy farming irrigation.
• Irrigated agricultural land used for grain, fruit, vegetable, and horticultural crops accounted for over 24 percent of irrigated agricultural land in New Zealand. Dairy accounted for 58 percent of irrigated agricultural land in New Zealand.

Irrigated agricultural land area on dominantly dairy farms increased 194 percent (from 131,000 to 386,000 hectares) in New Zealand between 2002 and 2022. There was a 203 percent increase in irrigated agricultural land area for Canterbury farms that were dominantly dairy from 90,000 to 274,000 hectares over the same period.

In 2022, irrigated agricultural land used for dairy (443,000 hectares) was more than double that of the second highest use, livestock (123,000 hectares).

Centre pivots and linear moves were the most used irrigation system by area in 2022 (462,000 hectares of New Zealand's total irrigated agricultural land area).

Where this data comes from

Stats NZ

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Farm numbers and farm size: Data to 2022
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About the data

This data comes from the Agricultural Production Statistics (APS) programme that started in 2002. The programme is funded by the Ministry for Primary Industries (MPI) and is a joint collection under section 24 of the Data and Statistics Act 2022.

Every five years Stats NZ conducts an APS census of all registered farms and undertakes a sample survey in the intervening years. Previous APS censuses were held in 2002, 2007, 2012, 2017, and 2022, with annual sample surveys in 2003-06, 2008-11, 2013-16, 2018-21 and 2023.

The population of the APS census and survey has evolved over time and has been based on Stats NZ's Business Frame from 2002 and Business Register from 2015.

A farm is defined as one or more blocks of land, managed as a single operation that engages in agricultural activity. This includes farming of livestock, horticulture, viticulture, nurseries, forestry, growing grain and seed crops, and land that could be used for these purposes.

Farms that are goods and services tax (GST) registered and earn over $60,000 during a financial year are the target population.

Farmers are asked to provide the land area in hectares that was irrigated during the year ending 30 June (that is, the midpoint of the year estimated). The 2002, 2017, and 2022 years ask how many hectares were actually irrigated, whereas 2007 and 2012 years ask how many hectares could have been irrigated. Consequently, we are only reporting on data from 2002, 2017, and 2022.

We report on total irrigated agricultural land in hectares for 2002, 2017, and 2022, both nationally and by region. We also report it by dominant farm type. The 2017 and 2022 data provide additional breakdowns of irrigated agricultural land by land use and irrigation system.

Dominant farm type generally refers to the activity providing the largest economic contribution to a farm. However, there are limitations to using dominant farm type as defined by primary earnings, as other farm types and earnings may also be present but are not accounted for.

Irrigated agricultural land totals and subtotals by system and farm type are as provided by survey respondents, and as such subtotals do not reconcile exactly to the New Zealand total irrigated agricultural land area reported here. For system totals, the difference between the total irrigated agricultural land and the sum of the systems of irrigated agricultural land is 14,301 hectares in 2022 (less than 2 percent of New Zealand's total irrigated agricultural land area). Survey questions recognise that hectares reported for irrigation systems may not reconcile total reported irrigation hectares due to multiple uses of the same area. The total value should be taken as the best estimate of total irrigated agricultural land area, rather than summing subtotals. When reporting on types of irrigation systems/farm use, the sum of the irrigation system/farm use has been used as opposed to the total reported hectares of irrigated agricultural land in New Zealand.

We used the following groupings for irrigation system types:

• travelling and sprayline
• flood
• micro
• centre pivots and linear moves.

Irrigated land: Data to 2022 Datainfo+ provides more information on irrigation system types.

Census years will not contain sampling error. However, there will be non-sampling error associated with the imputation process applied to the data, given that not all farms respond.

Survey years use a stratified sample design. The population is stratified by region, size, and dominant farm type. Survey years will contain sampling error because estimates are made about the population using a sample.

All datasets use a confidentiality method based on perturbed data that may change as part of a future APS release.

Spatial data for 2022 are confidentialised by aggregating meshblocks that have fewer than three farms with neighbouring meshblocks. The aggregation process is repeated until there are no meshblocks or aggregates that have fewer than three farms. A small number of meshblocks had numbers replaced with 'NA' because they had no neighbours and fewer than three farms. The data shown in the maps were categorised using natural breaks classification (Jenks natural breaks). Natural breaks create groupings where relatively big differences are inherent in the data. Values above zero and below the 99th percentile were used to calculate the natural breaks to ensure that outliers are not overrepresented in the maps.

Due to rounding to protect confidentiality, individual figures may not add up to national totals for any given year, and values for the same data may vary in different tables.

The compulsory registration level for GST is $60,000 so there is a partial and unquantifiable coverage of farms below this level. Therefore, the data does not completely represent the true distribution at a regional or national level.

Agriculture Production Statistics - DataInfo+ provides more information on the methodology used to produce agricultural statistics and related metadata of each census and survey.

Data quality

The accuracy of the data source is of medium quality.

Irrigated land is a partial measure of the 'Resource use and management and other human activities' topic.

Stats NZ and the Ministry for the Environment must report on topics related to the five environmental domains: air, atmosphere and climate, fresh water, land, and marine. These topics identify key issues within each domain.

Topics for environmental reporting describes the topics for each domain.

Data quality has more information about the criteria we use to assess data quality.

References

Cullen, R., Hughey, K., & Kerr, G. (2006). New Zealand freshwater management and agricultural impacts. Australian Journal of Agricultural and Resource Economics, 50(3), 327-346. https://doi.org/10.1111/j.1467-8489.2006.00338.x

Kienzle, S. W., & Schmidt, J. (2008). Hydrological impacts of irrigated agriculture in the Manuherikia catchment, Otago, New Zealand. Journal of Hydrology New Zealand/Journal of Hydrology (NZ), 47(2), 67. http://people.uleth.ca/~stefan.kienzle/Documents/Kienzle_Schmidt_HydrologyNZ_Manuherikia_Paper.pdf

Rankin, D. A., Orchard, S., & Brooks, A. (2021). Cumulative impacts of water abstraction on a recreational salmon fishery on the Rangitata River, New Zealand. Journal of Water Resources Planning and Management, 148(1). https://doi.org/10.1061/(asce)wr.1943-5452.0001488

Schallenberg, M., de Winton, M. D., Verburg, P., Kelly, D. J., Hamill, K. D., & Hamilton, D. P. (2013). Ecosystem services of lakes. In J. R. Dymond (Ed.), Ecosystem services in New Zealand: conditions and trends (pp. 203-225). Manaaki Whenua Press. https://www.riverlake.co.nz/wp-content/uploads/2017/09/Schallenberg-et-al-2013-ecosystem-services-of-lakes.pdf

Weaver, L., Karki, N., Mackenzie, M., Sinton, L., Wood, D., Flintoft, M., Havelaar, P., & Close, M. (2015). Microbial transport into groundwater from irrigation: Comparison of two irrigation practices in New Zealand. The Science of the Total Environment, 543, 83-94. https://doi.org/10.1016/j.scitotenv.2015.09.075

Wilcock, R. J., Nash, D., Schmidt, J., Larned, S. T., Rivers, M. R., & Feehan, P. (2011). Inputs of nutrients and fecal bacteria to freshwaters from irrigated agriculture: Case studies in Australia and New Zealand. Environmental Management, 48(1), 198-211. https://doi.org/10.1007/s00267-011-9644-1

Williams, E., Crow, S., Murchie, A., Tipa, G., Egan, E., Kitson, J., Clearwater, S., & Fenwick, M. (2017). Understanding taonga freshwater fish populations in Aotearoa-New Zealand. NIWA. https://waimaori.maori.nz/understanding-taonga-freshwater-fish/

Young, R., Smart, G., & Harding, J. (2004). Impacts of hydro-dams, irrigation schemes and river control works. In J. Harding, P. Mosley, C. Pearson, & B. Sorrell (Eds.), Freshwaters of New Zealand (pp. 37.1-37.16). New Zealand Hydrological Society Inc. and New Zealand Limnological Society Inc.

Archived pages

Archived December 2024:

Irrigated land - published April 2021