PENINSULA Link's landscaping looked less manicured after last week's storms.
Parts of the landscaped hillside on either side of the freeway slipped away with the heavy rain, raising questions over design and drainage.
Southern Way general manager David Clements said the rain had affected the freeway's landscaping.
"The recent significant rainfall impacted some of the mulch on Peninsula Link's garden beds which resulted in some minor slides on the batters between Cranbourne Road and Robinsons Road," he said. "We swiftly cleared up any debris from the road."
Mr Clements said additional planting would prevent the problem in the future.
"The planting and other landscape elements on batters will prevent the mulch and topsoil from sliding. The planting will take some time to be finalised and mature."
Mr Clements said these types of issues as a result of heavy rain were not uncommon or unexpected on new infrastructure such as Peninsula Link.