The New Zealand Transport Agency says the delay in rebuilding the Waiho Bridge is essential and will ultimately result in better access than the previously estimated timeframe.
NZTA assistant manager Pete Connors told The AM Show that the organisation's previous estimate of replacing the bridge in 7-10 days was optimistic.
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"We've been criticised in the past for being overly conservative and we said what's the best we could do and that stage that was the best we could do, in 7-10 days.
"Subsequently to that we've found out a few more things in terms of the detailed design and the methodology that has to go in, plus the decommissioning of the pretty stretched and buckled bailey that's on there, plus the piers."
A new estimate of 14-17 days was announced by NZTA on Sunday with the hopes of giving some certainty to local communities and the tourism industry. Connors says the delay will also result in access for more vehicles than the previous option.
"We were going to only have it open to busses and cars. With the new programme we'll have the replacement pier in place, so it'll be open to all Class 1 vehicles.
"We're much more confident with the 14-17 days [timeframe] and we'll be endeavouring to cut anything off that we possibly can."
Meanwhile, Westland Mayor Bruce Smith says the washout of the Waiho Bridge is costing the town of Franz Josef $1 million a day.
"It's the key, it's the main road, there's no way round it," he says.
"It is the only bridge that you have to go over if you're heading south or north."
The delay is bad news for businesses all along the Coast, who say they're losing out as tourists avoid the area.
One Hokitika café has been sending staff home early because there haven't been enough customers.
"There's a few tourists floating around but nowhere near as many as there should be at this time of year," says cafe worker Shannon Tozer.
The usually bustling main street of Hokitika was devoid of shoppers on Sunday.
"Just right at the edge of the peak of our season so we need to do everything we can to support our operators," Smith says.