A tanker has spilled up to 15,000 litres of milk into the Mataura River in Southland this morning.
The truck crashed into a power pole at Mataura about 3am, cutting electricity to about 150 customers.
The driver was uninjured but between 12,000 and 15,000 litres of milk leaked into a drain, sending it to the river.
An Environmental Southland spokeswoman said typically that much milk into the Mataura River would be a serious concern.
However she said it was lucky the area of the river where the milk filtered to was in flood overnight, which diluted the milk immediately.
"When the milk hit the river it would have diluted immediately and considerably [so] we're not anticipating any environmental affects," she said.
Sergeant Mark Booth said the road was closed after the crash but would be re-opened this morning.
Power has been restored to all 150 Southland homes affected by the outage this morning.
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