The full extent of flood damage in the region will not be known until the weather eases, which could take days, say officials.
Waitaki District Council Civil Defence public information officer Richard Mabon said there was also a reasonable chance of snow for the area in the coming days as a bitterly cold Antarctic front hit the country.
“We won’t know how much damage there is until the rain stops,” Mr Mabon said.
The rain, which had caused widespread flooding throughout the region, was set to continue for the next few days, he added.
The main threat to public safety stemming from the flooding would be the state of roads and bridges.
When the Oamaru Mail went to print, State Highway 1 and Seven Mile Rd remained closed north of Oamaru.
Yesterday afternoon the Maheno Bridge was re-opened to trucks and four-wheel drive vehicles, which relieved the temporary emergency welfare centre in Maheno.
About 130 people were stranded earlier yesterday afternoon and Civil Defence arranged a drop-off of food and blankets via helicopter.
The Kakanui and Otekaieke bridges remained closed last night as a result of the damage caused by flooding.
Mr Mabon said the integrity of the bridges was uncertain.
Civil Defence warned that anyone caught tampering with road signs or ignoring road closures would be dealt with by police immediately.
Yesterday, the State Highway was closed from Otematata to Oamaru, with a lot of back roads closed as a result of major surface flooding.
Some of the roads had been completely washed out and left impassable.
Mr Mabon said the floods clearly were the worst since May 2010.
“The thing with floods is that they are all unique,” he said.
He advised rural locals to avoid “non-essential” travel. “Residents are encouraged, if possible, to check on elderly, disabled or vulnerable neighbours and offer assistance,” Civil Defence urged. If any people were isolated and concerned they might need assistance, they should call 434 6400 or 433 0300.
Last night, more than 40 Waitai District roads were closed.
For road-closure updates, visit the Waitaki District Council website.
Local river and rainfall information can be checked on the ORC water info webpage www.orc.govt.nz/waterinfo or call 0800 426 463.
Farmers can contact the Otago Rural Support Trust on 0800 787 254.