High river levels may lead to the night-time closure of the Waitaki River bridges at Kurow this weekend.
Flooding in 1995 weakened piers on the bridges, making them vulnerable to damage during high river flows, a New Zealand Transport Agency spokesman said.
A decision would be made tomorrow on whether the rivers were high enough to warrant closing the bridges between 7pm and 6am.
The nearest alternative river crossing is 70km away at Glenavy.
A decision on the bridges this weekend comes at the same time as Southland and South Otago residents keep a wary eye on river levels.
Water levels in Southland and South Otago have receded in the past 24 hours and all roads have reopened but that could change this weekend with a heavy rain warning in place.
In Clutha, the last of the three roads closed because of flooding reopened yesterday, but Clutha District Council staff are keeping a close eye on the levels of the lower Clutha River.
The swollen Tokomairiro River, crossed by State Highway 1 at the southern entrance to Milton, has dropped significantly in the past day but its levels were also being monitored.
Environment Southland officials hope the province may miss the worst of the next predicted belt of heavy rain.
Environmental management director Warren Tuckey said the level of the Makarewa River had dropped steadily after this week reaching the fourth-highest flood peak on record.
Heavy localised rain in the area had closed several roads but other Southland rivers had not flooded significantly.
Information on river levels and flows are available online at Environment Southland: www.es.govt.nz.
