Fish and Game says a tougher approach is needed to get Taranaki farmers to finish fencing and planting their waterways.
The regional council is involved in a project to improve water quality and stream life by getting farmers to protect nearly all waterways.
The council has a target of improving 90% of all waterways by 2015 but only 10% of farmers have carried out their riparian plans so far.
Those farmers are now eligible for a completion certificate, which may form the basis of a regulatory requirement.
Fish and Game spokesperson Allen Stancliff says the rate of implementation needs to increase and he believes regulation will come.
Council chief executive Basil Chamberlain says the majority of farmers are actively working on their planting and fencing plans.
He says he is not worried if the target is not accomplished by 2015 as it would only be a year or two out.