Awarua upoko Sir Tipene O’Regan was among the 500 people who celebrated the day at Te Rau Aroha Marae in Awarua (Bluff) — one of three places where Ngai Tahu tupuna signed the Treaty of Waitangi in 1840.
Leaders and kaumatua across the country gathered to "share a kai", recognise the relationship between Crown and iwi, and discuss the importance of freshwater.
“Our commemorations today at Awarua have been full of extraordinary variety, but also genuinely felt and expressed hope — a hope that we, Ngai Tahu and the Crown, will have a more informed and better quality relationship in our future," Sir Tipene said.
"Water is very important for Maori and Aotearoa as a whole.
"We need to maintain the cleanness, the quality and quantity for future generations."
He said Waitangi Day was important to emphasise that councils, the Crown, farmers and other community sectors needed to work together to achieve that goal.
Energy Minister Megan Woods spoke to the crowd and reiterated a messaged from Prime Minister Jacinda Ardern about the partnership between Crown and iwi.
"Many of you heard, in recent days, Jacinda speaking — again — about the bridge — the bridge that we must create as a nation, a place where we cultivate, not where we have expectations of one party or the other would cross fully to the other side, but one where we will meet and one that we can share our strengths."
Waihopai Te Runanga o Ngai Tahu representative Michael Skerrett said it was a day of remembrance for "all Kiwis" as the founding document meant the beginning of two cultures coming together in partnership.
"New Zealand is probably one of the most democratic countries in the world, and one of the most peaceful in the world. It is all built in this foundation of the Treaty of Waitangi."