Neighbours of a Queensberry farm are concerned about earthworks ''obliterating'' a stream and negatively impacting on the ecosystem.
The Central Otago District Council received two submissions opposing an application for retrospective land-use consent on a farm on the north side of Poison Creek.
The application was made on behalf of owner Lynn Wills at the council's suggestion after it was notified of earthworks on the property.
A report by council planning consultant David Whitney said Mr Wills breached district plan rules by digging a 1km and 3m wide ''bench'' into a slope near the border of his property to enable the building of a stock-proof fence and provide space for a water-system pipe.
The application said the council had ''not made any real effort to inform or educate the rural community and the rural contracting and fencing industries of the existence'' of the rule.
Mr Wills intended to mitigate adverse effects by topsoiling and reinvigorating the excavated land with dryland pasture mix, it said. The legal boundary of the site went through Poison Creek, which would be impractical to build a fence through and would require Otago Regional Council permission.
An opposing submission by neighbours Christopher Heine and Brigid Costello said the work ''completely obliterates'' parts of the waterway by covering it in spoil.
''The once strongly flowing stream that was Poison Creek has been reduced to a trickle. Many trees have been destroyed or are likely to die from their trunks being swamped by earth spoil.''
Mr Wills notified the couple of the work but did not respond to a request for more detail, they said.
Neighbours Sunny Collings and Young Read Woudberg Trustees Ltd submitted that ''Mr Wills could reasonably be expected to have known at the time of purchase of the land, and certainly after, what rules applied to it''.
Mr Wills should remove all fill from the creek bed and cover the cost, they said.
The regional council inspected the site in February and ordered Mr Wills to undergo mitigation by November to improve the flow of the stream, they said.
Mr Whitney's report said all adverse effects could be mitigated and recommended the application be granted.
The application will be heard at a hearings panel meeting in Alexandra next Tuesday.