The residents of two other houses evacuated after the fatal landslide yesterday are staying with family and friends.
Mr Greally said many roads were blocked by minor landslips and people should consider whether it was safe to travel to work today.
He warned people to "curb your curiosity" and avoid visiting the house that was destroyed on Kaiteriteri-Sandy Bay Rd in Marahau, near Motueka, after the 200m-long land slip about 1.15pm yesterday.
Mr Greally said police were contacting members of Ms Hivon's family, who would be going through "horrific times".
Neighbours had tried frantically to find her before emergency workers arrived.
A Marahau volunteer firefighter, who did not wish to be named, said the slip "absolutely demolished the house and smothered the occupant in dirt".
"It was a disaster zone - demolished, one wall standing."
He said rescuers did their best to recover Ms Hivon but "it was all in vain".
"They finally managed to recover the person involved and administered CPR, but unfortunately it was too late."
Motueka Fire Station chief fire officer Mike Riddell said she may have cried out to her rescuers.
They had yelled out to her to see if she was there. "They believe they may have heard someone yelling but then it stopped," Mr Riddell said.
"They did find her reasonably quickly, I believe they did whatever they could do to revive. I don't believe they had much success."
Mr Greally said he expected rain to ease today.