Parts of Castlecliff and the city's airport could be lost to the sea unless repairs are done to lower Whanganui River structures including the north and south moles.
The city's airport, harbour, Wharf St boat ramp and parts of Castlecliff are at risk, the Whanganui District Council's infrastructure and special projects committee heard today.
"Seafront Rd would again truly be Seafront Rd and the Castlecliff playground would be more of an aquatic park," manager Rowan McGregor reported.
Councillor Rob Vinsen went further: "The safety, the very existence of Castlecliff, is at risk."
Repairs of about $16.5 million are needed.