The Crown has confirmed a cash top-up payment of $138.5 million will be paid to Ngai Tahu and Waikato-Tainui, following confirmation treaty settlements have exceeded the $1 billion mark.
Both iwi negotiated a special relativity mechanism with the Crown as part of their Treaty of Waitangi settlements.
This week, the Crown and South Island-based iwi confirmed to the Otago Daily Times that clause was triggered for the year ended June 30, and the $1 billion mark exceeded.
The top-up mechanism effectively entitles Ngai Tahu to 16.1 per cent and Waikato-Tainui 17 per cent of all future settlements once the $1 billion in 1994 dollar terms has been exceeded.
Ngai Tahu kaiwhakahaere (chairman) Mark Solomon said the iwi always thought the Crown would exceed the $1 billion fiscal envelope, and the relativity mechanism acted as an insurance for future generations.
"We were the first to go through the first tribunal process, and the Government had come out with the fiscal envelope policy ... so it was an insurance policy."
The Crown has calculated in 1994 dollar terms that the amount payable to Ngai Tahu was $45.6 million, $68.5 million when adjusted for inflation.
Waikato Tainui will receive a cash payment of $70 million.
Minister for Treaty of Waitangi Negotiations Chris Finlayson said it was the decision of both iwi when to exercise their rights under the relativity mechanism.
"After the initial relativity payments, both iwi may seek a further payment in accordance with the relativity clause in five years' time in relation to further settlements reached over that intervening period."
Mr Solomon confirmed the payment was cash as opposed to shares or assets, and the iwi had people reviewing the Crown's calculations.
Any dispute over figures could take up to six months to resolve.
"But once we request payment, the process should not take long."
He said the iwi always believed the amount would be triggered, "but we had no idea how long it would take".
However, time was not an issue for the iwi and its nearly 50,000 members.
"We are pretty careful with the way we handle our money, at the forefront, always, is the people in our community and the money will be invested wisely for this generation and future generations to come."
Te Runanga o Ngai Tahu representatives would meet this month to discuss the payment.