Agricultural activity

This section provides information about agricultural activity and its relationship to recreational water quality in Aotearoa New Zealand, using data sourced from Statistics New Zealand. 

The agricultural sector plays an important role in New Zealand’s economy. However, poorly managed livestock and agricultural production can have a major impact on the environment. 

Recreational water bodies can be contaminated with effluent from farm animals or chemical runoff of fertiliser product. Faecal bacteria from this waste can cause gastrointestinal or respiratory diseases, while chemicals such as nitrogen and phosphorus commonly used in fertilisers can contribute to the growth of toxic algae.

Agricultural activity has a major effect on recreational water

Agricultural land use and livestock access to waterways can increase the runoff of nutrients, sediment, and faecal contaminants into rivers and lakes, particularly during rainfall events (Kronvang et al 2020). Pathogens such as E. coli, Campylobacter, Cryptosporidium, and Giardia are associated with waterborne illness and have been linked to areas with higher livestock densities, especially dairy cattle (Bunyaga et al 2023; Wilson et al 2019). Management practices such as stock exclusion, riparian buffers, controlled fertiliser use, and improved grazing can help reduce these impacts on recreational water quality (McDowell 2021).

Overall, livestock numbers are in decline, with Manawatū-Whanganui recording the highest density

New Zealand’s total livestock numbers declined by around 34% since 2002, driven mainly by a major reduction in sheep numbers. Dairy cattle were the only category to increase overall since 2002, though their numbers have begun declining in recent years. Livestock density varies widely by region, with Manawatū-Whanganui recording the highest density in 2024.

The area of agricultural land is decreasing

Between 2017–2022, the area of land in New Zealand used for agricultural purposes decreased by 5.7%, an area equivalent to 800,000 hectares. The largest decline was in the Canterbury, Southland, and Otago regions.

In 2022, agricultural land accounted for nearly half of New Zealand’s total land area (49.5%). Mixed sheep and beef farming remains the dominant land use; however, its share declined alongside grazing land, while forestry expanded.

Irrigation is increasing, but almost exclusive to the South Island

The total area of irrigated agricultural land in New Zealand grew slightly, reaching 761,900 hectares in 2022. Most of this irrigation is concentrated in the South Island, particularly Canterbury, which accounts for 63% of the national total.

Information about the data

Livestock numbers

Source: Statistics New Zealand - New Zealand Annual Agricultural Production Surveys, and five-yearly Agricultural Production Censuses. For more information, visit the Statistics New Zealand Agricultural Production Statistics webpage. 

Agricultural land use

Source: Stats NZ. 2024. Agricultural Production statistics: Year to June 2024 (final). Data available from Agricultural Production Statistics (accessed May 2025).

Irrigation

Source: Statistics New Zealand (2020). Consented freshwater takes. Retrieved from https://www.stats.govt.nz/indicators/consented-freshwater-takes