NZ collapsed hillside
© MARK TAYLOR/FAIRFAX NZ
A couple living on the edge of a collapsed hillside are dreading the next deluge.

Mercer residents Hayley and Robert Schwass watched as the paddock over the fence cracked open and slid down into the valley below.

It smothered a stream and a natural dam formed but they now fear it will fill up and burst. "We've got a lake down there now," Robert said.

"And the ground is so soft it's only a matter of time before it bursts."

Part of the road at Mercer has slipped away after heavy rain
© MARK TAYLOR/FAIRFAX NZ
The torrential rain that caused widespread flooding and landslides across Auckland and the Coromandel had eased when the pair noticed something strange happening over the fence.

Hayley was about to get into their car on Sunday when she saw the earth move. In a few minutes the landscape to the Kellyville Rd farm had changed dramatically.

"It was a bit like slow motion," she said. "It would stop for a second and you'd think it was done and then it just kept going down."

Three days earlier, a small crack formed in the paddock after a week of stormy weather. By Saturday there was "quite a deep crack going through it".

On Sunday afternoon the pair stood and watched their boundary fence get buried in an avalanche soil.

They could hear the pine trees cracking as the dirt uprooted mature trees and snapped them in half. "Our perfectly straight fence then wriggled down there," Hayley said.

Contractors take a seat while assessing the damage on a road near the slip
© MARK TAYLOR/FAIRFAX NZ
"From the roadside it's pretty spectacular."

The pair weren't too worried about losing their fence. "Our concern is down there, to do with the water," Hayley said.

The couple have contacted the Earthquake Commission. EQC covers damage to residential land, within certain limits, that has been caused by storms and floods.

The view of the slip face from the Schwass' residence
© MARK TAYLOR/FAIRFAX NZ
Around the corner on Koheroa Rd large cracks have ripped open the tarseal. The road was also damaged in the storm and it was closed on Tuesday while contractors assessed the scene. It is unclear how long the road will be closed.

The cause of the slip and repair options are still under investigation, according to Waikato District Council.