A 30km/h temporary speed limit is currently in place, with traffic control staff on-site 24/7 to monitor the area.
Stop/go traffic control will be in place from 6pm to allow contractors to water blast the road, the statement said.
"While our contractors will endeavour to finish the clean-up tonight, they may need to return to the site tomorrow night to undertake further water blasting."
Anyone using the road while travelling for essential supplies or services under alert level 4 should take care, plan ahead, adhere to the temporary speed limits and follow the directions of traffic management staff and signage.