Farmers may be asked to sell their land, or change its use, to prevent the quality of Lake Okareka's water deteriorating further.

The suggestion follows seven months of planning and meetings by a working party made up of representatives of Environment Bay of Plenty, Rotorua District Council, Department of Conservation, Fish and Game, iwi, landowners and Lake Okareka residents.

Lake Okareka Ratepayers and Residents Association representative Rod Stace said the change of land use for farms could have a financial impact on residents but was needed for the health of the lake.