Canterbury Regional Council's new land and water plan doesn't go far enough in setting limits on nitrate leaching to improve water quality in the region and waterway pollution could worsen, critics say.
The council has for the first time approved a plan seting controls on nitrate levels, which have been linked to ground water and river pollution in parts of Canterbury.
The council has accepted the recommendations of commissioners who heard submissions on the plan.
Commissioners Peter Skelton says once it is in full effect next year, the council will require farmers and land users to manage their operations and improve their environmental performance so the decline in water quality will be reversed.
However, agribusiness consultant Alison Dewes, who made submissions as an expert witness, says the new rules won't do anything to reduce nitrate leaching over the next few years below the already toxic levels in some catchments .
The grand-parenting approach could also penalise farmers who are making effects to reduce nitrogen losses and it won't prevent a further decline in the health of Canterbury rivers, Dr Dewes says.
Green Party MP Eugenie Sage says the plan risks increasing, not reducing, nitrate pollution of groundwater because it will effectively allow existing leaching to continue and grow.
The plan relies too heavily on farm environment plans and agribusinesses using best management practice, and stronger rules are needed, she says.