UPDATED: 5.19PM The sale of Ashburton's water is being described as a kick in the guts for residents.

The District Council is selling 10 hectares of land on its business estate, with a consent for the owner to take 40 billion litres of water from the local aquifers.

The consent, which allows 45 litres to be taken every second, was approved by Environment Canterbury.

Concerned resident Jen Branje said there's no guarantee the town has an infinite source of water so it should be protected, and not used for corporate greed.

Ms Branje said she and others are hoping to start a community group to get some answers.

She believes the reason the Council hasn't been more open is because it fears a public backlash.

Green MP Catherine Delahunty said Canterbury is one of the most stressed regions, in terms of water.

"This is cowboy behaviour on behalf of companies who are coming into the country, not just in Ashburton, but in Hawke's Bay and other places, and just taking our water," she said.

"ECan [Environment Canterbury] and the district council allowing this to happen without proper consultation is another kick in the face to residents, but also to the future."

Ms Delahunty said this wouldn't make sense to anyone, apart from some small-minded people in control of the process.

She doesn't believe Ashburton residents want to see 40 billion litres of artesian water given away, to a bottled water supplier.

The Ashburton Council has hit back saying it's been through a lengthy public consultation with both residents and iwi.

Mayor Angus McKay said consent's been granted with a discharge consent of 60 litres a second.

"Putting 60 litres per second in the ground water through a single pit line with native plants to filter it so it's clean enough and taking 45 litres out as part of an environmental park we're setting up".

And Environment Canterbury's consents planning manager Tania Harris said at this stage the organisation is happy with the consent but will be watching.

"We're satisfied with the off set from the recharge of water. But once those consents were activated we would be able to monitor those activities and if we have any concerns, if there are any adverse environmental affects, then we can review the consent conditions".

Mayor McKay said there's been ample opportunity for people to have their say.

He said the Council has jumped through every hoop necessary to make sure the process is positive for the district.

Meanwhile, Labour is calling for a law change on the sale of local water resources.

Labour MP Clayton Cosgrove said we need to question what New Zealanders are getting from the deal.

He said currently companies can pump the water for very little cost, sell it overseas and rake in the sheaves.