The Whanganui River claim is likely to be settled this year and its people will begin four days of preparing and celebrating on February 28.
"We need to prepare for what that brings for us. This will get people ready and excited," Nancy Tuaine said.
She's part of a group organising the occasion. It follows an iwi (tribal) development summit in 1999 and other youth initiatives since.
The days are for descendants of the Whanganui River - both those living nearby and those who live elsewhere.
This year it all starts on February 28, the usual day for celebrating the occupation of Pakaitore/Moutoa Gardens at the gardens. A whanau (family) triathlon begins the day, which continues with the usual school visits, kapa haka, bands, entertainment and speeches.
The following day, Friday March 1, a summit is held at Putiki Marae. Called Raukotahi 2013, it aims to help people born after 1983 find a pathway into leadership roles.
Ms Tuaine said everybody was needed in some kind of role, whether in companies, at schools, on marae or in boardrooms.
There will be keynote speakers during the day - on finance and accountability, and on legal obligations. People from Tainui, who are experienced in succession planning, will talk about that. People being prepared for particular roles could be given scholarships to train for them.
The summit will end with a huge dinner under marquees at the marae, to celebrate 25 years of the tribe's annual river journey, the Tira Hoe Waka.
"Being on the Tira is one part of being part of the iwi. The next part is to continue those roles by being involved and participating," Ms Tuaine said.
The following day, Saturday, will be for marae to celebrate the river itself by competing against one another in waka ama races.
Day four will be for tamariki (children), with activities and a lunch at Kowhai Park/Waipakura.
Both Whanganui's neighbouring iwi, Nga Rauru and Ngati Apa, are planning tribal celebrations next month as well.
The Ngati Apa Nga Wairiki Iwi Festival, Apa Rising, is on March 16. Nga Rauru's Te Toi Ahurea runs from March 8 to 10.