Farmers wanting water for irrigation in the upper Waitaki catchment, upstream from the Waitaki dam, will need approval from Meridian Energy.
Environment Canterbury (ECan) will start considering, in Twizel and Christchurch from September 22, more than 120 new or renewal applications, mostly for irrigation, for water from west of the dam.
But, before a three-man panel appointed by ECan will even consider those, applicants are being told they need "derogation approval" from Meridian.
That follows a High Court decision in 2004 that ruled Meridian and other existing users at that time had the right to all the water in Lake Tekapo.
The Aoraki Water Trust wanted water from the lake for a $35 million irrigation scheme for up to 30,000ha in the Mackenzie Basin and South Canterbury.
But the court ruled that would derogate Meridian and other existing users' rights to water for which they had consents.
That means any new applications for water above the Waitaki dam would effectively be taking it from Meridian, or other existing users.
While the decision looked at Lake Tekapo, it effectively ruled that all water west of the Waitaki dam was allocated to Meridian and other users.
Meridian and the Mackenzie Irrigation Company have reached a deal for Meridian to supply up to 150 million cu m of water a year for irrigation.
That would be made available to farmers who applied for consents and had approval from Meridian.
The chairman of the ECan panel which will hear applications, Prof Peter Skelton, said that without "derogation approvals" from Meridian the panel would be unable to grant consent "as a matter of law".
There was no point in hearing any applications in such circumstances, he said.
If there were any issues associated with Meridian's refusal to give approval, applicants should bring them to the panel's attention well before hearings started.
