The Heritage New Zealand Pouhere Taonga Act 2014 makes it unlawful for any person to modify or destroy, or cause to be modified or destroyed, the whole or any part of an archaeological site without the prior authority of Heritage New Zealand. If you wish to do any work that may affect an archaeological site you must obtain an authority from Heritage New Zealand before you begin.
An archaeological site is defined in the Heritage New Zealand Pouhere Taonga Act 2014 as any place in New Zealand (including buildings, structures or shipwrecks) that was associated with pre-1900 human activity, where there is evidence relating to the history of New Zealand that can be investigated using archaeological methods.
If you are planning to work on a site where there has been human activity before 1900, then your first point of contact is the regional archaeologist at Heritage New Zealand’s Otago/Southland Area Office. The office contact details can be found here: Offices- Heritage New Zealand. They can talk you through the archaeological authority process.
More information can be found on Heritage New Zealand's website.