Barwon Water is responding to a collapsed sewer main on Settlement Road near the intersection of High Street, Belmont, in Geelong.
The sewer main is located six metres below ground and repairs are likely to be complex and may take several weeks.
One lane (westbound) will be closed until repairs are completed. A temporary, above-ground sewer line has been installed to maintain service. Baron Water reports there may be a slight odour at the site.