A council has stamped a flooding hazard notice on a retirement village despite giving it the go ahead to build a new apartment block just a year-and-a-half before.

Photo: Supplied.

The Thames Coromandel District Council put the notice on the Richmond Villas title in December 2018 after granting resource consent for the 73-apartment-block in July 2017.

The villas were developed in the mid-2000s and since then elderly people have been buying their right to occupy one of the sea-front units in Thames.

What they have not been aware of is that last year the council put a notation on the building's title that the land it was built on what is considered at risk of flooding, overland flow, storm surge and tidal effects.

In January 2018, a storm surge came over the seawall and flooded the entrance to the existing units, just six months after the council gave the property owner consent to build the additional apartment block.

In late 2017, climate scientist James Renwick spoke to the council and the community about the risk of sea level rise and coastal erosion.

He said it had been known for a while that coastal flooding was an issue in Thames.

"To my mind there was a lot of information around demonstrating that the coastal region, or the most low-lying parts of Thames, were pretty vulnerable to sea level rise and that on general principles it wouldn't be a good idea to be looking to allow more building work happening near the waterfront."

The council would not speak to RNZ but put out a statement saying it issued the resource consent for the apartments before the Ministry for the Environment released its coastal inundation guidance in late 2017.

However, the council could have used similar guidance issued by the Ministry in 2008 which wanted councils to incorporate in their planning the risk of a sea level rise of at least 80 centimetres out to 2090.

The council also based its apartment consent decision on a 2001 engineering report.

Professor Renwick said it was curious why the council referred back to a nearly 20-year-old report.

"I'm surprised and a little bit disappointed that consent was issued in 2017 when really I think there was plenty of information around to say this wouldn't be a very good idea."

The council said it was required to issue a notification where a hazard existed, and it had informed the Richmond Villas' owners.

Owner Colin Parker also did not want to be interviewed but said the hazard notation was news to him.

He has since gone back to the council and said they told him he had been sent a letter - a letter which he said he never received.

Mr Parker said the land the complex was built on was substantially higher than a lot of Thames.

Retired associate professor of law Kenneth Palmer said there had been cases where councils had been liable for damages for not informing potential purchasers of properties of this type of detail.

"It could raise the possibility that if the council did know and didn't say anything about it that the council could be liable for some loss of value."

Dr Palmer said the move had consequences as to whether the property would be insurable and what the premium would be.

Mr Parker said the complex's 120 residents provided their own content insurance but the complex covered building insurance.

Insurance Council chief executive Tim Grafton said he wanted councils to take greater care with consenting, particularly when it involved a vulnerable population such as the elderly.