The residents had been told the one-lane bridge, which links Clydevale with Lawrence, would be closed for three weeks.
It was scheduled to reopen this weekend but the council confirmed contractors had discovered the repairs would take longer.
About 20 disgruntled residents met yesterday to vent their spleen at the situation, which for most means any trips to nearby Clydevale or Balclutha, 35km away, involves an extra 45-minute journey via Clarksville, near Milton, before heading south.
Those trips normally take 25 minutes but resident Avis Rishworth said her most recent journey took more than an hour.
In a statement last night, the council acknowledged the lengthy closure would have a major impact on road users and said it was looking at providing "limited alternative access" across the river.
It hinted pedestrian access might be possible but vehicular access might not.
Mrs Rishworth, who hosted yesterday's meeting, said the community was prepared to accept the three-week closure, but having the bridge out of use for 10 weeks was unacceptable.
She was among a chorus of people beneath the bridge yesterday, calling for the council to, at the least, install a footbridge and possibly even a ford across the river so residents and other road users could cross.
Council district assets manager Jules Witt said the need for more time-consuming repairs to the bridge was found only when timber decking had been removed.
The top sections of five steel beams supporting the timber had experienced "significant deterioration" from rust.
"Peoples' safety is paramount and we have no option but to ensure the bridge is safe before it is reopened."
Lawrence-Tuapeka ward councillor Geoff Blackmore said the council was looking at a wide range of options and the issue might be debated at Thursday's district assets committee meeting.
A small raft, used in this year's Balclutha raft race, has been modified and is used as a "mini punt" to ferry Balclutha-bound workers across the Tuapeka River.
Gaye Cowie, who lives in Tuapeka Mouth, has used the raft twice this week.
She pulls herself and the raft across the water using ropes, a task that takes some physical prowess and five minutes.
She also has to climb up dirty river banks in her work clothes.
