The twin bridges on State Highway 82 at Kurow may be closed again tomorrow so workers can finish clearing debris from around the piles.
Initial work was done last Saturday, but the machinery available had insufficient reach to remove all the debris around the bridges.
It is feared the debris could cause scouring and put pressure on the piles of the 129-year-old single-lane bridges.
New Zealand Transport Agency senior assets manager Colin Hey said yesterday that while the plan had been to close the bridges all day on Saturday, they were closed only for a short time in the morning.
The work had to be rescheduled to tomorrow and the bridges would be closed for short periods to allow access for machinery.
They would open for five minutes on every hour and half-hour to let traffic cross, or to clear the bridges to allow emergency vehicles over.
Mr Hey said machinery for the work was still being finalised and the closure plans would be confirmed today.
The debris built up during flooding in January and February. The flooding closed the bridges to traffic, except pedestrians and cyclists, from February 8 to 17.
