Frustration is growing over delays in repairing a major washout on State Highway 4 in Whanganui, left virtually untouched since the 2015 flood.
Whanganui mayor Hamish McDouall said if the damage got any worse it had the potential to cut the town in two and cost taxpayers millions of dollars.
In June 2015, floodwaters gouged 80m out of the riverbank on Anzac Parade and brought down the riverside walkway and the edge of the road at the intersection of Portal Street.
A month later another section of embankment came down, claiming the walkway from Taylor Street to the City Bridge.
Mr McDouall said the situation was serious.
"If there was another inundation that ate into State Highway 4 that could really split Whanganui in two because that is the main route really between one side and the other."
Mr McDouall said the delay had been unacceptable.
He said the New Zealand Transport Agency - which is responsible for the repair work - had to recognise that if the City Bridge was cut off it would have implications well beyond Whanganui.
"You can always tell when the Desert Road is closed because Anzac Parade becomes very very busy and so if it continues to scallop in like it has been the second route down the country would have to alter.
"It is really really important ... it's a pinch point."
Local resident and former regional manager of Transit New Zealand, Errol Christiansen, said the work was taking an unprecedented amount of time.
Mr Christiansen said the delay seemed symptomatic of how roadworks were approached now.
Road Transport Association regional representative Tom Cloke said he was losing confidence in NZTA.
But Al Loney, whose business Al's Workshop was directly across from the washout, was a little more understanding.
"The roads still available to be used out here and there's pedestrians walking across the road and past here so it's probably not affecting to many people."
Mr Loney said he was actually more worried about the disruption to his business when construction began.
NZTA regional transport manager Ross I'Anson said the agency had been waiting for consents to be signed off and now expected to start work in September or October and be done by December.
The project would cost about $6 million, and NZTA would pick up the bill, he said.