He said the continuous rain had saturated the bank where the slip occurred, which made it softer and looser.
"We're going to be monitoring the Wellington roads and banks, because there's lots of rain coming down so we have to monitor the sites to make sure we keep them safe."
Other smaller slips have come down in Thorndon and Newtown, and the Naenae train station subway is flooded.
The Chocolate Fish cafe is located on Shelly Bay Rd, and manager David is hoping the road is cleared as soon as possible, so customers can get through.
"At the moment we've cancelled a couple of staff, and we're still debating whether we should cancel some more because we don't know when they'll open it."
When the Herald visited the cafe at around 10am, there had only been one customer all morning.
"A couple of people have been texting me trying to get through, but they won't go the long way because it'll take ages."
The City Council have asked commuters to take extra care as there are reports of surface flooding in low lying areas including parts of Lambton Quay.
Yesterday MetService severe weather forecaster Mads Naeraa-Spiers told the Herald there was lots of unstable land in Wellington, being hilly.
"It's been raining pretty much since Monday, so the ground is soggy and there will be slips."
MetService has now lifted the heavy rain warning that was in place yesterday, but it's still looking like a wet weekend ahead for Capital residents.