Horrell Contracting foreman Dave Kenny said excavation for a footing to build a concrete wall began about four weeks ago.
"We had about 50mm of rain last night. The diversion was washed out," Mr Kenny said.
One person evacuated their house voluntarily yesterday as water pooled in Milton's lower streets, Clutha District Civil Defence and emergency services officer Selwyn Vigers said.
"There were a few roads with water on them. One person left voluntarily.
"There was no water in the house, but there was water all round the place," he said.
About 60mm of rain fell at Balclutha yesterday, while West Otago recorded about 35mm.
Waitahuna farmer Murray Paterson said since it started raining on Monday, he had recorded about 76mm.
His property was not on low-lying ground, and Mr Paterson said his waterways had coped well with the deluge, but the Waitahuna River was up and some of the low-lying properties in the Waitahuna Valley had water on them.
Wanaka
The Wanaka and Upper Clutha areas have escaped much of the heavy rain that has drenched coastal Otago.
Makarora had received 4.5mm of rain in the 24 hours to noon yesterday (33mm in the past seven days).
During the same periods, Cascade Hut received 19mm (37mm), the Matukituki Valley received 1.5mm (20.5mm) and the Albert Burn 20.5mm (57mm).
Freezing temperatures in the mountains brought more fresh snow to Wanaka's skifields yesterday.
Cardrona Alpine Ski Resort has 22cm at its base buildings, after 12cm of fresh snow overnight.
Treble Cone now has up to 30cm in the Saddle Basin but very little around the lower home basin.
About 10cm of slushy snow was covering the Pisa Range yesterday, which is home to the Snow Farm, Snow Park and Southern Hemisphere Proving Ground, and it was still snowing there at noon.
Queenstown
Queenstown had scattered showers on Tuesday and yesterday.
In the 24 hours to 1pm yesterday, 18.5mm of rain fell at Peats Hut on the Shotover River.
Colder temperatures resulted in snow on the mountains above 1200m.
The MetService advised snow levels would lower to 400m by late afternoon yesterday and to 200m overnight in the Southern Lakes region.
Palmerston/East Otago
Water levels on the Shag River continued to fall yesterday, but the Pleasant River south of Palmerston remained in flood.
State Highway 85 from Palmerston to Ranfurly was open and State Highway 1 was closed north of Palmerston until mid-morning.
Flooding closed Factory Rd, Switchback Rd and Patterson Rd on the outskirts of Palmerston yesterday.
Snow was predicted to fall to between 200m and 300m above sea level in East Otago overnight.
East Otago High School and the local primary schools were closed yesterday.
