Forty per cent of dairy farms required to lodge a resource consent application with Horizons Regional Council have not done so.
A total of 229 dairy operations were required to have lodged an application by January 1 this year under the regional council's One Plan, which aims to limit nitrogen pollution of waterways.
The One Plan - adopted by the council in 2014 - limits nitrogen leaching by intensive farm operations, namely dairy, commercial horticulture, cropping and intensive sheep and beef farming.
Figures released to the Chronicle under the Official Information Act reveal that only 137 of the 229 dairy operations which came under new rules have lodged consent applications. The new rules took effect on July 1 last year, and farms had six months - up until January 1 - to apply.
Of the 137 applications received by Horizons, 94 have been processed and granted. None have been declined.
Horizons regulatory manager Greg Bevin said the 92 dairy farms which had not lodged a consent application were "engaged in the wider process", which included working with the consultants on applications.
"Our focus is still on achieving a good quality outcome for all parties involved rather than focusing on the numbers," Mr Bevin said.
No enforcement action has been taken by Horizons, but Mr Bevin said if people refused to engage in the process it would be considered.
Meanwhile, 80 of the 94 consents granted have been issued as restricted discretionary consents, which mean farms are allowed to leach more nitrogen than permitted under the One Plan rules.
Restricted consents are allowed under the plan, but only as exceptions and only if farms meet the One Plan limits within four years.
The Chronicle revealed last year that some farms had been given consent to leach nitrogen at more than three times the target set in the council's plan.
Horizons has said the method of calculating nitrogen leaching has changed since the One Plan was adopted, and more farms than originally estimated would struggle to meet targets.