A popular walking track in the Wellington suburb of Ngaio has been closed after a 20-tonne sewage 'sucker' truck toppled off a path above it and came to rest upside-down on a tree.
Wellington Water said the 12m long truck was being driven by a Dawson's contractor when two wheels of the truck left the path and it tipped over on Wednesday.
The driver wasn't injured in the incident, which happened in Trelissick Park between Ngaio Gorge Road and the walkway.
"Once a year the truck is sent down to suck any grit and rocks out of the sewer pit," Chris Mathews of Wellington Water said.
The truck was on its second trip of the day and was empty at the time.
"The truck's fall was broken by a big tree," he said.
Wellington City Council has fenced off the path beneath and closed the Trelissick Park walking track until the $500,000 truck is removed.
Wellington Water said it had hoped to try and remove the truck on Friday, but poor weather made the work too dangerous.
Mr Mathews said the truck will be removed by two trucks pulling it out in a tandem motion.
The wet weather forecast means it's unlikely to be removed until next week when the ground has dried out enough and it is safe to do so.
Wellington Water is working with its insurer and is investigating how the incident happened.