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.
"The infrastructure has not been maintained since the 1960s and is now showing clear signs of escalating deterioration," McGregor said.
The question quickly became: who pays?
Councillors agreed the Horizons Regional Councilshould contribute, although McGregor noted "they're not overly keen to pay".
"Either way it's not much fun for ratepayers which letterhead the bill comes in on,"
Vinsen said it was time to take the issue to the Minister of State Services for a ruling on Horizon's obligations.
"We have been talking for years to Horizons. It's their mandated role. We need to get tougher about this," Vinsen said.
Philippa Baker-Hogan agreed and said more discussions with Horizons would be a "talkfest for the next decade".
McGregor said the council was unaware of the state of the various structures until 2010 when it took back ownership.
A new report from port engineers Tonkin and Taylor highlights 15 items that need repair, including five, worth $750,000, that require immediate attention.
The most expensive work was needed on the north and south moles at a cost of $13 million and had to be done within five to 10 years.