A decision to delay public discussion on a Plan Change 10 affecting run-off in rural Rotorua areas has been blocked.

Known as PC10, the controversial appeal undertaken by the Rotorua Lakes Council was unsuccessful.

A recent Environment Court decision did not overturn at original finding of how the nutrients on agricultural land surrounding Lake Rotorua could be managed.

Though not confirmed, the cost of the council's decision is thought to have been close to $1million.

At today's final Rotorua Lakes Council meeting of the present term, the council closed down discussion on the matter after it was raised by councillors Peter Bentley and Mark Gould.

Mayor Steve Chadwick says the court's finding was an interim decision, therefore it could not be discussed in open meeting.

Her ruling was confirmed by chief executive Geoff Williams, who said the matter was best discussed in the publicly excluded session.

Plan Change 10 limits the amount of nitrogen entering Lake Rotorua from surrounding use of land.

The Environment Court's interim decision favours a ‘sector range approach' over managing the lakes preferred by the Rotorua Lakes Council, Central North Island Iwi Land Management Ltd and various forestry companies.