"Disturbing" environmental damage in the Waipahi and Catlins river catchments has left Otago Fish and Game councillors shocked at what farmers can do to their land.
A report to the council late this week outlined environmental damage believed to have been caused by intensification of farming practices in the upper catchments of the rivers.
Fish and Game officer South and West Otago Morgan Trotter said these examples represented a continuing loss of freshwater habitat and would "worsen water quality and quantity concerns downstream".
"Unacceptable" damage had been done in a tributary of the Waipahi River where a farmer had drained a large part of the catchment of a creek by putting in large tile drains which cut the bed of the creek in two places and ran parallel to it, Mr Trotter said.
There were also concerns about a large wetland, known as the Cairn Swamp, being drained.
The Kuriwao lease land was owned by the Otago Regional Council and leased to a farmer.
"Large-scale attempts have been made to drain and plough this important remnant peat wetland."
In another case, a new dairy farm at Tumbles Creek posed a potential risk to the water quality of the stream, which was a tributary of the Waipahi River, he said.
Other concerns included drainage of several small creeks in the headwaters of the Catlins River.
They had been excavated and replaced with tile drains or had suffered large-scale bed disturbance.
Each case had been raised with the Otago Regional Council, which had investigated, but no action had been taken.
Cr Terry Broad said the damage highlighted in the report was "quite disturbing".
"I thought they couldn't get away with this sort of thing any more," he said.
There were also worries about the damage being done to populations of native fish, like whitebait.
Cr Dan Rae suggested the report be sent to each Otago Regional councillor for their information.
Fish and Game Otago chief executive Niall Watson said there had been a number of issues in the past two or three years which had exposed problkems in the wording of the regional council's water plan, which needed to be adjusted.
