Environment Minister Nick Smith says claims that new rules around fresh water mean lower standards and higher chances of swimmers getting sick are wrong.
Mr Smith stood by the new measures, a day after the Government pledged to make 90 per cent of New Zealand waterways swimmable by 2040.
The plan includes 56,000 kilometres of fencing by 2030, and will require rivers and lakes to meet standards at least 80 per cent of the time.
"My view is that it is a fair standard, it has been developed with the very best quality scientists, and what's more, it's consistent with the level that has been set by the World Health Organisation," Dr Smith told TVNZ's Breakfast today.
"It's consistent with the level that's been set in the US and Europe, and that's why people are being pedantic and unreasonable.
"It's a good standard."
The new level states that for a river to be considered excellent it cannot exceed a new E coli level of 540 per 100ml more than five per cent of the time.
Critics, however, say the new rules will mean more people will get sick.
"An appropriate standard would be to go back to the Ministry of Health's acceptable standard, which is a 260 E coli count over 100, which gives you a one in 100 chance of getting a campylobacter infection, and that's what New Zealanders have been asking for," Marnie Prickett from Choose Clean Water NZ told Breakfast.
"I'm saying to the government give New Zealanders what they're asking for, not the standard you've just made up."