A public health academic is warning the government's Resource Managament Act (RMA) reforms could cause more emergencies like Havelock North's water contamination.
The Māori Party has agreed to back the government's overhaul of the Resource Management Act, finally giving it the numbers it needs.
It is the government's third attempt to change the country's most important environmental protection tool, as it tries to encourage house-building in Auckland.
Senior lecturer in environmental health at Otago University Alex Macmillan said it was often forgotten that the RMA had a major role in protecting human health.
Dr Macmillan said the government was playing with fire when it weakened protections.
"Havelock North was a real wake-up call for people to remember that clean air and clean water, low pollution and a safe climate are fundamental building blocks for preventing illness and keeping people well."
She said the Māori Party seemed to have got good changes for iwi resource management, but missed the danger to all New Zealanders, including hauora Māori, from limiting public input.
Environmental groups have used the RMA to stop many large developments, and have been fighting the planned changes at every step.
Forest and Bird solicitor Sally Gepp feared the Māori Party had missed the bigger picture.
"They appear to be pleased with the outcomes that they have achieved in terms of the references to iwi as kaitiaki, and I support them in that, but I really hope they have not traded away New Zealand's birthright in the meantime", Ms Gepp said.
More than 800 submissions were made on the reforms, and most were critical of major elements.
Ms Gepp said they seemed to have been largely ignored.
Outdoor recreational advocacy group Fish and Game agreed, but its chief executive, Bryce Johnson, said they would not know for sure until they saw the final text.
"This bill has been almost universally opposed before the select committee yet the government now has got the authority to push it through. So we're all waiting to see the actual wording of the changes.", Mr Johnson said.
The minister leading the reforms, Nick Smith, disputed all these criticisms and said, if anything, the changes would help public health by improving overcrowded housing.
He said the reforms were modest and necessary.
It was not possible to make the Resource Management Act more timely and efficient and less costly if all groups kept all of their objection powers and ability to appeal projects all the way through the courts, he said.
Dr Smith said he expected the select committee to publish a revised bill either late this year or early next year for its final push through Parliament.