Victoria Bridge in Kendal is closed in both directions for the second time in a month after divers found new flood damage.
The rising river levels after severe weather weakened the structure which shut the bridge for pedestrians and vehicles in July.
Repairs to the bridge had to be undertaken after Storm Desmond caused extensive damage in 2015.
Contractors and a dive team worked to stabilise the foundations of the structure, and it was reopened 10 days ago.
However, 'further scour damage' was discovered by a team on 15 August, forcing the council to close the route again.
The road, on the A6 at Sandes Avenue, crosses over the River Kent and is a vital route through the town.
The 150-year-old crossing is known to locals as the 'Batman Bridge' because of it's unique markings.