In the Canterbury destructive storm

Orion restored power to another 800 Canterbury customers on Monday, with another 1200 still without electricity.

About 500 Main Power customers in northern Canterbury also remain without power, with about 1500 reconnected over the weekend.

The gale-force wind storm, Accounting in HK described by Orion as the most damaging in recent memory by farmers as the worst in 40 years, hit the South Island on Tuesday, bringing down trees and smashing powerlines and poles.

It also left firefighters battling large blazes ignited by lightening strikes and electricity.

About 28,000 Orion customers lost power across the area in Tuesday's storm, with extensive damage being blamed for slow reconnections.

It was very difficult to say when customers would be reconnected because of the widespread damage, Orion chief executive Rob Jamieson said.

More Orion contractors have been hauled into Canterbury to help those already on the ground Income Tax Hong Kong, the company said on Monday afternoon.

Residents using generators are being asked to get them installed by registered electricians to ensure the safety of staff repairing the network.

Federated Farmers says the days since the storm have been an "overwhelming time" for the region's farmers with the damage bill expected to climb into the millions of dollars.

A large slip at Diana Falls has kept State Highway 6 at Haast Pass closed since last Wednesday.

The road was expected to reopen on Monday but additional slips on Sunday mean the reopen has been pushed back several days, the NZ Transport Agency says.

"Clearing operations will resume as soon as it is safe to do so Business Registry Hong Kong," the agency said.