Coastal residents are taking a deputation to the Christchurch City Council today after a peer review found flaws in the council's coastal hazards report.

Last year the report from Tonkin and Taylor showed 18,000 properties were vulnerable to coastal flooding, as sea levels rise, almost 6000 of which were at risk of erosion.

Those properties now have their vulnerability identified on LIM reports which can reduce land values and increase insurance costs.

Christchurch Coastal Residents United chairman Tim Sintes said the peer review's found parts of the report aren't fit for purpose, so they're doing a deputation.

If the council accepts the updates the next step is working on a timeline and informing residents of what's next.

Mr Sintes said interest in the case is huge.

"New Zealand is watching us, cities are watching us, our coastal towns are watching us and here we are still dithering around after a clear message from the hearing panel that it shouldn't be on the LIMs," he said.