Some respondents to the aggregate survey did not specify a value for their production. To account for this, and to allow an estimate of total value, the data provider have applied the average reported value for a given commodity to the missing values for that commodity.
Gold production is taken from the annual reporting permit holders provide to NZP&M. The value is calculated by applying the average price per unit taken from the royalty returns provided to NZP&M.
The response rate to the aggregate survey impacts the completeness of the data reported. The percentage of respondents for 2021 was 54.45% (367 respondents out of 674 quarries surveyed), and for 2022 was 53.81% (374 respondents out of 695 quarries surveyed).
Please note that the survey response rate includes all responses received including those reporting no production, sold quarries and those who responded to advise they would not provide production data.
The production statistics feature coal, industrial minerals and metallic minerals groups. Metallic minerals produced are gold, silver and titanomagnetite ironsand. Rock, sand, and aggregate are produced for roading and construction and are vital for the development of New Zealand’s infrastructure.
A number of other industrial rocks and minerals are produced for local and export markets. They include bentonite, various clays, diatomite, perlite, pumice, serpentine, silica and zeolite.
Method of collection/Data provider
New Zealand Petroleum & Minerals collects aggregate production for all quarries that have a permit for Crown-owned minerals that account for approximately half of all quarries in New Zealand.
New Zealand Petroleum & Minerals surveys all other aggregate producers but they are not statutorily required to supply their production figures.