A group from Kohupatiki marae in Hawke's Bay has started a water monitoring project of the Clive River.
The waterway, which local Maori call the Ngaruroro awa, has been a traditional source of food for the hapu for hundreds of years.
Project head Aki Paipper says the first stage involved planting thousands of flax and other native species along a one kilometre strip of land next to the awa.
She says the focus is now on improving the quality of water and discovering what is contributing to its poor condition.
Ms Paipper says when she was growing up at Kohupatiki the substrate of the awa was gravel and ideal for fish to live in, but today there's an extensive amount of sediment and weed growth in the river.
She says the hapu has also launched Project Patiki, which aims to increase the population of patiki or black flounder in the Ngaruroro awa.
