He said he had talked to residents of Rauhomaumau Rd in Tutukaka which slipped in April following bad weather, and believes that road had warning signs similar to the conditions he is concerned about.
"All of the slumping is on the side of [Matapouri] Rd where there is a steep drop off."
He said the road is popular, particularly in summer, with many people flocking to the beaches.
"Like the Mermaid Pools, they come from all over the world and they want to go on this road."
Mr Feigel said since he sent the letter, the pothole had been filled in.
"It seems to be an ongoing problem. It gets filled in, the patch wears off."
He wants to see a permanent fix.
As for the slumping, he estimates there are about six different areas where a crack has formed as part of the road has dropped lower than the other part.
Mr Feigel said it had been happening for a couple of years.
"They patch it then it gets worse. We've been watching it get worse locally since last summer.
"I don't know how much worse it can get before the road falls away."
He said the worst two parts were about 700m and 1.5km from the Tutukaka Marina turnoff.
He said the road wasn't made for the kind of traffic it experiences today.
"If it slips away, all the people who live out here are in for a lot of extra expense and inconvenience."
A council spokesperson said both the sites mentioned in Mr Feigel's letter had been checked by a roading inspector.
"The pot hole was repaired on July 28 and we have programmed more permanent repairs at this site during the summer season.
"Similarly, Matapouri Rd will be crack sealed, and more permanent works carried out over summer."
Mr Feigel said sealing the cracks was not a permanent solution.
"It doesn't address the problem with the different levels of the road."
The council spokesperson said Rauhomaumau Rd had been repaired and the road would be sealed before Christmas.
A 20m section of road on Rauhomaumau Rd dropped up to a metre when the waterlogged land under it gave way during post-cyclonic rains in April, cutting access to 20 homes.
A Rauhomaumau Rd resident, who did not want to be named, said they were still working through their insurance claim process with EQC.