The weather-beaten Ashburton Bridge has reopened to light traffic, but more testing is needed to determine if it's able to support heavier vehicles after severe flooding compromised its structure.
The bridge, which is part of State Highway 1, crosses the Ashburton River and connects the town to the southern suburb of Tinwald. It's the primary transport route for southbound travellers.
The Canterbury region was battered by wet and wild weather over the weekend, with torrential rain causing the Ashburton River to swell significantly. The town was badly hit by flooding, leading the District Council to declare a state of emergency.
The bridge was closed on Tuesday morning after motorists reported a "slumping" in the structure. Engineers later determined the bridge had been weakened by the severe flooding, with photos showing a significant buckling in the roading about 100m from its northern end, with the barrier visibly bent in one place.
Speaking to The AM Show on Wednesday, Ashburton Mayor Neil Brown revealed the rapidly swirling water of the Ashburton River had dislodged one of the piles.
"It swirled underneath one of the piles and dropped it down. It hasn't weakened it, it's just dropped it - about six inches. They tested it last night for light vehicles and it worked, it didn't move, so it's strong enough to take the lights," he explained.
The bridge was reopened by the New Zealand Transport Agency (NZTA) late last night for light vehicles with speed restrictions in place.
Fourteen-tonne concrete blocks have been used to stabilise the damaged piles, but further testing is needed to determine if the bridge can hold the weight of heavier vehicles.
"They're going to put up to 40 tonnes on it and see if it can take the heavy vehicles across. After 2pm, we'll know if heavy vehicles can go across the bridge or not," Brown said.
The NZTA will then assess the piles to determine if any longer-term work needs to be undertaken, he added.
An alternative route is currently in place for heavy vehicles, with trucks finally back on the road after numerous closures heavily restricted regional travel.
The severe weather and widespread road closures also disrupted the supply of goods, raising concerns around stock levels in several badly affected areas. Some customers encountered bare shelves and limited produce in supermarkets, including in Queenstown and Dunedin.
But Foodstuffs South Island CEO Steve Anderson told The AM Show any shortages are minimal and temporary, and waved off suggestions that panic-buying locals had depleted supermarket stock.
The Ashburton Bridge will be closed between 10am and 2pm on Wednesday for further testing.
