The Government is to give a cluster of Hawke's Bay iwi and hapu money up-front to invest in the proposed Ruataniwha dam.
It will pay $20 million to Heretaunga-Tamatea, ahead of its full treaty settlement and financial compensation.
The tribal collective has always signalled its interest in the water scheme.
However, tribal negotiating body He Toa Takitini chair David Tipene-Leach said it might not use the money to invest in the dam.
There was currently no decision to invest in the project but the negotiating team wanted to secure the putea (fund) in case the people supported taking a stake in the scheme.
The Hawke's Bay Regional Council says the dam is not commercially viable under its resource consents because of the environmental constraints imposed, and two major investors have pulled out.
As part of the payment, the Crown had asked Heretaunga-Tamatea to acknowledge that the Crown was not advising or endorsing any decision made over the dam.