So far this season, only one of the dairy farmers prosecuted in the past year has reoffended but the Otago Regional Council is still concerned at dairy effluent pollution levels.
The council has so far completed 300 inspections this season, with 15 farms under investigation for significant non-compliance, a report to the compliance committee said. Last month 13 cases were reported.
Cr Bryan Scott was disappointed the report noted that some dairy farmers expressed no concern when their discharges were pointed out.
"We need to do something different. What tools can we use to get a different outcome?"
Director of resource management Selva Selvarajah said the council got tough last season and prosecuted 24 farms for non-compliance, with the majority of cases resulting in "relatively minor" fines, of between $2000 and $37,000, compared with fines handed out in other regions, Dr Selvarajah said.
"The court has a significant role to play in what sort of deterrent they could use."
Under the Resource Management Act, courts could impose a fine up to $200,000 or imprison for up to two years for such offences, he said.
"It is a matter of applying these tools, but in fairness to the court it is the first set of cases [in Otago]."
Given that only one farmer out of the 24 prosecuted had reoffended this year was quite positive, although there were still about 70 inspections to go and some farms needed to be revisited, Dr Selvarajah said.
"From our perspective we have used all the tools we have in hand so we are reliant on the court system to make cases more serious."
Chief executive Graeme Martin said he was also not convinced there was anything additional the council could do other than continue taking a hard line.
Cr Stephen Woodhead said the council had held field days, sent out newsletters and written to all dairy farmers, so he did not think the council was missing anything.
Cr Doug Brown said there was "no magic bullet" and "tough love" was a good way to describe the council's actions in future.