Rescuers tried to refloat the remaining cetaceans during high tide on Friday morning but only had partial success.
Up to 300 whales have died and volunteers are trying to send more than fifty more back out to sea, while trying to keep them as comfortable as possible, local media reported.
A desperate plea went out for volunteers to help save the remaining animals, and hundreds turned out to do just that.
Earlier, as they waited for the tide to come in, volunteers had tried to keep the whales cool and damp and cool by covering them with blankets and dousing them with buckets of water.
"Every hour they spend on the beach, their chances drop", Mr Lamason said.
About 50 whales were successfully refloated, but 80-90 have re-stranded on the beach, reportsRNZI.
Efforts to save the whales have been put on hold for the night as the incoming tide made it too risky for volunteers.
The photos below show volunteers rapidly working to save the surviving whales at Farewell Spit.
Hundreds of locals managed to rescue the survivors after forming a human chain to refloat the whales.
The spit's long coastline and sloping beaches make it hard for whales to navigate away once they get too close, earning its sand banks the nickname "whale trap".
There are concerns the 100 re-floated whales and another pod of about 200 more are threatening to strand at Farewell Spit again. Pods attempting to avoid predators, such as orcas, may also swimming close to shore and get stranded.
The mass stranding is deemed the third largest in New Zealand since records dating from the late 1800s. In 1985 about 450 whales stranded in Auckland.
On top of that, pilot whales are notorious for stranding themselves.
Pilot whales rely heavily on sonar for their navigation, and the sandy and muddy beaches on Farewell Spit provide poor echoes, giving whales the impression that they are still in deep water.
Mass beachings are not uncommon at Farewell Spit, where it is believed the gently shifting sandy beaches may not be picked up by the whales' echolocation.