The Manapouri Boating Club Inc appeared in the Invercargill District Court last month after admitting clearing the indigenous vegetation.
The club had asked the council if it could remove the plants in 2010 and 2014 and was informed it needed resource consent to do so.
In late 2020, the council received a complaint regarding the removal of the trees.
The boating club made a retrospective application the next month.
The Department of Conservation and Forest and Bird opposed the application and suggested the clearance was a significant breach of the Southland District Plan.
After various site visits by the council, it estimated at least 70 beech trees had been cut down, and two were mature.
Other native plants were also removed.
"The loss of forest canopy provided by the beech trees resulted in alterations to the forest’s understorey at a local level," the council determined.
The clearance had created a minor loss of habitat for native birds and insects, it said.
The council "unusually" stated it did not want a penalty to be imposed on the defendant.
Prosecutor for the council Shelley Chadwick said that was "due to the position of the current council in the community and the role that the defendant plays".
Counsel Rex Chapman said the club accepted responsibility for the actions of its members who did not believe consent was required.
"The vegetation clearance was carried out by a group of well-intentioned club members who did not have the direct authority of the club’s committee," he said.
Removing the vegetation was part of maintenance of the access track to the boat club ramp, and that involved removing overhanging trees that were rotten and could fall, he said.
The boat club immediately acknowledged its culpability by applying for retrospective consent, Mr Chapman said.
The number of trees cut down was in dispute as the trees had leaders, making it difficult to distinguish whether a tree was individual or part of another tree, he said.
Club members had voluntarily planted at least 200 native trees and the club had incurred costs of almost $40,000 as a direct result of the offending.
Judge Prudence Steven accepted the boating club did not wilfully circumvent the resource consent process.
She imposed a penalty of $11,000, with 90% of that to be paid to the council.
She also made an order that the defendant replant the area and maintain the vegetation for at least 36 months.
felicity.dear@odt.co.nz , PIJF court reporter
