The Hawke's Bay Regional Council says there is a strong commitment to solving water quality issues in the upper Mohaka and Taharua rivers south-east of Taupo.
Nutrient runoff from farms in the area is being blamed for a decline in water quality, which in turn is severely reducing the quality and number of brown trout.
The council's strategic development manager, Helen Codlin, says the formation of a stakeholder group is the first step in addressing the issue.
She says the group includes farmers in the catchment, Fish and Game, Federated Farmers, the Department of Conservation and Fonterra.
The group, which will work with the regional council and the Taupo District Council, has its first meeting later this month.