Towyn was hit by flooding in 1990 when sea fences were breached

New plans will be referred or refused in Towyn, Kinmel Bay and Pensarn.

Hundreds of Towyn homes were evacuated in February 1990 when sea defence barriers were breached in a gale.

A 2004 study claimed the chance of a repeat event was one-in-200 years but new data suggests the "tidal risk" might be as high as one-in-75 years.

Now the computer modelling of the risks involved will have to re re-run.

In the meantime, no new planning applications will be given the go-ahead, councillors have decided.

Around 5,000 people were forced from their homes and businesses in the flooding which hit Towyn 17 years ago.

Since then millions of pounds have been spent on coastal protection schemes.

The local authority, the then Welsh Development Agency and Environment Agency Wales ordered an assessment of future flood risks.

'Overtopping'

But in a report to Conwy's planning committee on Wednesday, the council's head of planning, Peter Dethridge, is set to tell members that computer modelling of the risks involved will have to be re-run.

His report to the committee said new data suggested the study "may not provide a sound basis for ... the assessment of risk probabilities in all areas and scenarios".

The report reads: "Information has recently emerged that has raised doubts over the assessment contained in Conwy Tidal Flood Risk Study particularly as it relates to the risk of overtopping of the Foryd Banks".

Mr Dethridge's report said that Environment Agency Wales was far more likely to object to a planning bid in the light of this information.