Ngai Tahu says the government needs to work closely with iwi to resolve the long-standing question of who should own or control fresh water.
The Waitangi Tribunal has found Māori should have greater participation in management and decision-making over water and says it's time for the government to ensure that happens.
More than 75 percent of the irrigated land in New Zealand is within Ngai Tahu's South Island territory.
Dr Te Maire Tau is co-chair of the freshwater committee at Te Runanga o Ngai Tahu.
