David Robertson, who lives near Beaumont, said a very small, nameless creek topped its banks in the storm and nearly took out his mailbox.
He believed more than 70mm of rain fell in 30 minutes.
It was "very loud, continuous thunder and lightning, huge hailstones and overflowing spoutings. [It was] unlike anything we have seen before", he said yesterday.
The creek had nearly dried up before last night’s downpour, he said.
"We were actually going to check our shop in Lawrence, but would have needed a boat. No way we were going to safely make it down tonight."
Roads affected
Police said there had been extensive surface flooding on State Highway 8 between Millers Flat and Raes Junction and they closed the road between Raes Junction and Lawrence.
Motorists were asked to take alternative routes or delay their travel.
A spokeswoman for the Clutha District Council said this morning that Rongahere Rd was closed overnight between Beaumont and John O'Groats Rd due to flooding and fallen trees.
The New Zealand Transport Agency advised that SH8 between Millers Flat and Lawrence has been reopened under a 30km/h temporary speed restriction.
Council contractors were assessing roads throughout the district this morning, including in West Otago, Waipori and the Lawrence areas, the council spokeswoman said.
Surface flooding may be present on roads and motorists were urged drive to the conditions and take care.
The Central Otago District Council placed general flood warnings on Ranfurly and Patearoa community areas due to torrential rain.
It advised caution as the extensive amount of water lifted manhole covers in the streets.
Scattered showers and isolated thunderstorms were expected to hit much of the east coast of the South Island, including Southland, southern Central Otago, and inland Clutha, Dunedin and Canterbury.
