Meridian Energy has asked the New Zealand government to introduce tradeable water rights in a move that could unlock some of the country's water resources for other uses, including irrigation.

Meridian spokesman said a tradeable water rights system like that emerging in Australia had some application in New Zealand. Meridian had already had some informal discussions with the Government on the matter.

Under the Australian system, farmers were able to sell their water rights to one another, either regionally or interstate. Water was priced according to demand and could be sold on an annual or permanent basis.