However, pedestrians and cyclists will be allowed to use the bridges daily between 6am and 10pm from today, the New Zealand Transport Agency has decided, giving some direct access between Kurow and Hakataramea.
It was hoped the assessment could be carried out yesterday to determine what damage the bridges on State Highway 82 had suffered from flood flows in the lower Waitaki River and what repairs would be needed.
Agency area manager Colin Hey said the river flow was still too high to examine the damaged pier on the north bridge, and it might be Monday before that could be done.
"The inspection should provide a clearer idea of the options available to open the bridges again.
"Because of their importance to the state highway network, getting the bridges operational is a high priority, although safety of road users has to come first," he said.
The 129-year-old bridges, originally built for rail and road traffic, were closed on Tuesday night.
Plans are in place to ensure emergency service vehicles can get across if needed.
That left only the SH1 bridge at Glenavy or travelling on SH8 through Fairlie and Lake Tekapo as the two routes still available to bypass the Waitaki River.
The two single-lane bridges are due to be replaced, at an estimated cost of about $15 million, with two two-lane bridges.
Construction could start in 2012 and be completed by 2014.
The high flows in the Waitaki River have been caused by heavy rain earlier this week.
Mt Cook received 185mm on Monday, bringing its total over seven days before that to about 550mm.
The rain has filled Lakes Tekapo, Pukaki and Ohau beyond their maximum operating levels and caused floods in up-country rivers, the Ahuriri River reaching 350cumecs compared with its normal flow at this time of the year of 10 to 15cumecs.
That forced Meridian Energy Ltd to spill water through the Waitaki system.
The Waitaki River hit a high of 1550cumecs on Tuesday and yesterday at 3pm was 1493cumecs.
Meridian and Environment Canterbury have both warned that flows in the lower river are likely to be in that range for the next few days.
"This high flow follows on from the flooding of about a month ago where some damage occurred to river protection works on the lower Waitaki River.
Farmers and other landowners adjacent to the river are advised to monitor their own situation very closely as changes in river flow patterns can occur," they said yesterday.
