The Canterbury Regional Council has had 'a wake up call', it says, after Forest and Bird accused it of failing to act against farmers who seriously breach their water rights.
Official Information Act data obtained by Forest and Bird has shown there were 376 serious breaches of water consents in the 2013/14 year.
These included extracting too much water and not having water meters installed, making it impossible for Environment Canterbury (ECan) to monitor how much water farmers were taking.
Forest and Bird said some streams were completely drained, and one farm illegally took 31 million litres of water from Manuka Creek over 42 separate days.
Environment Canterbury chief executive Bill Bayfield said the council was taking the accusations seriously.
"It's going to be a wake-up call for all of us that the community and the broader community in New Zealand are expecting us to drive the water regulations through, and ensure that we're absolutely accurate in making sure that people use only what they are consented to use."
The Canterbury region has nearly 6000 water-take consents that need to be measured and reported, which the council said was three times more than any other region in New Zealand.
However, Mr Bayfield said there was enough staff to keep an eye on water use.
"I don't think it's a case of staff, the water regulations came out in 2012 and the government moved to ensure everyone using a significant volume of water had a water meter.
"We're now in the situation of over 90 percent of farmers having those meters, and over 90 percent of the farmers supply us with data.
"What we're moving to is to mop up the final consent and what you're seeing from Forest and Bird is a signal that for them we're not doing that fast enough," Mr Bayfield said.
He said the level of evidence needed to take someone to court was very high, but abatement notices and infringement notices had also been issued.
"I doubt we can get the standard of evidence lowered, but what we can do is learn from practice."
Mr Bayfield said some of the serious water consent breaches in the 2013/14 year were due to inaccurate meter readings.
"A number of those are just a learning curve as New Zealand is going through learning to water meter and learning to drive off that information to enforcement and prosecution where necessary."
Mr Bayfield said an infringement notice could be up to about $700, but if the breach then went on to prosecution it could be up to $200,000.