The Dunedin City Council said it had deployed "wet weather overflow" barriers in South Dunedin's Surrey St "as a trial".
The barriers were acquired by the DCC late last year and were designed to divert wet weather overflow away from properties.
DCC city services general manager Scott MacLean said the council was continuing to monitor the city’s 3 Waters and roading networks – which were performing as expected – while putting a number of precautionary measures in place.
This includes maximising pumping through the Portobello pumping station and activating an overflow at the Tahuna wastewater treatment plant, which allows partially treated and heavily diluted flows to be released into the ocean.
“These precautionary measures are helping alleviate pressure on the city’s stormwater and wastewater networks, particularly in South Dunedin, by freeing up additional capacity in both," Mr MacLean said.
Despite some localised reports of of surcharging in high-risk areas of South Dunedin, including Surrey Street, the steps taken to free up network capacity appeared to be working.
The move comes as the city's heavy rain watch is upgraded to an orange heavy rain warning.
Meanwhile, at the University of Otago, a large tree has fallen on a footbridge that crosses the Water of Leith on Leith Walk.
A large crane is on site to move the tree and the bridge is closed until further notice. People are advised to avoid the area.
"Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible."
Council contractors are out checking Dunedin's water network amid heavy rain from the tail of the storm that ravaged the lower North Island.
"The focus is on high-risk areas, and our contractors can’t be everywhere at once, so if you spot a blocked mud tank grate – and you’re able – please clear the debris on to the footpath for our contractors to collect later," the council said in a Facebook post.
"Bags, sand and shovels are available on site, but we encourage people to come ready to fill their own bags.
"We’re continuing to monitor the situation and we’ll provide further updates as needed."
The DCC also reminded people not to swim or collect shellfish at the city's beaches for the next 24 hours.
As of about 1pm, two roads in Dunedin were closed due to flooding - Ashmore St in Halfway Bush and Old Brighton Rd.
MetService meteorologist Alanna Burrows said yesterday a watch for heavy rain and severe gales had been issued for the eastern South Island, as a deep low east of the country tracks slowly southwards.
"We’ve had this low pressure system centred just offshore to the east of the North Island and it’s drawn a huge amount of moisture down from the tropics.
"So it’s this big moisture-laden low with tropical air wrapped around it.
"It’s pushing slowly southwards and as it does so, it’s pushing lots of bands of rain across the country and that’s why we’re starting to see that heavy rainfall.
"We’ve seen it over the North Island, and then as it tracks southwards we’re expecting that heavy rain to push into the east coast of the South Island."
MetService is forecasting the heavy rain to peak between 10am and 2pm.
Heavy rain was also expected to fall further north to Oamaru, but to a lesser extent.
She said it had been "fairly dry" for Dunedin so far this year.
"So by comparison, this is definitely going to be a wet day for Dunedin and it could quite likely be the wettest day you’ve seen so far this year."
Because South Dunedin was quite low-lying and flooded relatively easily, she said it was wise for residents to be prepared.
"Follow advice from the Civil Defence and stay alert with the latest heavy rain watches and warnings on the MetService website."
"There’s definitely a heightened awareness at the moment, given all the other impacts around the country.
"If MetService do upgrade it to a warning and once we get an understanding of how much rain they are predicting and what the potential impacts would be, emergency management will just communicate out on our social media and on our website that it’s gone to a warning.
"In terms of any localised activity like sandbagging, that would come from Dunedin City Council."
The same storm ripped roofs off houses, knocked trees over, closed roads and cut power to thousands in the Wellington area yesterday morning, when gusts hit 193kmh on Mt Kaukau and 128kmh at Wellington Airport.
Some schools were closed, residents were advised to work from home, ferry crossings were cancelled and Air New Zealand paused flights in and out of the capital, Napier and Palmerston North yesterday.
Several flights to and from Dunedin were disrupted.
