Rain causes 'catastrophic' driveway collapse in Sydney

Wet weather is hampering efforts to stabilise a unit block in Sydney's northern beaches after a landslip at a building site just metres from it.

Residents from the 12 units in the three-storey block in Collaroy have been evacuated as have those from the other neighbouring home, Fire & Rescue NSW said.

Emergency services were called to Frazer Street just after 5am on Tuesday because of leaking from a ruptured gas main.

Sydney's recent torrential rain caused part of the side of the construction site to collapse, rupturing a gas main.

A driveway adjacent to the building site, which is within four metres of the unit block, then collapsed.

Fire crews and engineers have been assessing the site all day, but the constant rain is hindering efforts to support the area.

"Engineers are liaising with builders and residents," a Fire & Rescue NSW spokeswoman said.

Search and rescue specialists have reported further slight movements in the area.

"There are plenty of emergency crews on scene looking at how best to deal with the situation," she said.

Police are also on site.

NSW mops up as wild weather eases

A severe weather warning for southern NSW has been cancelled as state Emergency Services begin mopping up after heavy rain and fierce winds overnight.

SES fielded 300 calls for assistance on Monday night, with the Sydney and Illawarra regions worst affected by the foul weather.

Many residents were affected by leaking roofs and fallen trees and branches, and flooding isolated the small community of Towrang near Goulburn overnight, where about 400 people were affected, the SES said.

Rain causes 'catastrophic' driveway collapse. Photo: Supplied by NSW Fire & Rescue

Conditions have since eased and the severe weather warning has been cancelled for the Sydney, Hunter, Illawarra and South Coast.

"The situation will continue to be monitored and further warnings will be issued if necessary," the Bureau of Meteorology said on its website.

However, a marine wind warning has been issued, forecasting gale force winds for coastal areas in the Coffs, Macquarie, Hunter, Sydney and Illawarra regions early on Tuesday morning.

The BOM says dangerous surf conditions will continue into Tuesday with waves of up to four metres during the day.

"Large and powerful surf conditions are expected to be hazardous for coastal activities such as rock fishing, swimming and surfing," BOM said.

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