This trenching is a priority and it's hoped it will be completed in a couple of months but the collapsed wastewater pipe is far more complicated.
It's a unique piece of infrastructure and there's no solution yet on how it will be decommissioned, meaning there's no timeframe for when the road and footpath will return to normal.
However, a project team has been appointed to solve the problem and geotechnical testing has begun.
Wellington Water held a public meeting tonight to hear from concerned businesses and residents.
Knit World owner David Goldingham is worried people think businesses are closed along Willis St, especially when the trenching work gets into full swing.
He thinks a recent sale with direct marketing has saved his business from the full impact of the pipe collapse so far.
"When people want to get somewhere they will, and with our sale, yes they have, but this week and the following weeks we'll soon find out if people are being put off by it all."
City GPs practice manager Lorraine Wood is concerned about patients being able to access medical care.
"People who are walking along the footpath can, but if you have restricted mobility then you can't park outside because then you have to clamber over a pipe to get into the practice, likewise anybody on a stretcher or in a wheelchair can't access their vehicles."
There is an alternative route through the basement of the building, which is usually exclusively for staff, but there are also restrictions with that access due to commercial construction around Feltex Lane.
City GPs has 11,500 patients.
"If our patients can't access us for medical care then they're forced onto hospital services or after-hours services, which cost more", Wood said.
Access was the biggest issue raised at the meeting, for example, the entrance to Trinity Hotel's car park is just outside the collapsed pipe cordon, but that could change when work to decommission it begins.
The area is also a popular route for students which one resident said would turn into "chaos" when they returned for the 2020 academic year.
Wellington Water has given assurances contractors on site will be available to help businesses and residents with gaining access to their properties.
Service delivery chief adviser Ian McSherry said an initial estimated completion date for the Willis St work of February 28 was "very optimistic".
"We'd usually spend two years for the planning, investigation, design and construction."
But he said everyone was working hard to get the job done as quickly as possible as they transitioned from the emergency to recovery phase.
Greater Wellington Regional Council has launched an investigation into the causes and effects of the wastewater discharge.