Leighton Holdings Ltd (ASX: LEI) says that a number of the group's Queensland construction and contract mining operations may be affected due to extreme weather events.

Leighton Holdings' chief executive David Stewart said group operating companies were taking all necessary precautions to safeguard the well-being of their employees during this period.

"These measures include temporary project shutdowns and leave provisions for employees to provide assistance to their families and local communities," Mr Stewart said.

Since late December, rain and consequent flooding have impacted the Group's contract mining activities in Queensland with varying degrees of severity. Based on current information some mining operations have recommenced whilst others remain on reduced rosters as dewatering continues. There have been no injuries to personnel, or any significant loss of plant or equipment.

The group's construction projects are located across the state, with the majority in South East Queensland. These areas are currently experiencing extreme rainfall and flooding and it is too early to assess the impact.

Mr Stewart said operations have ceased at the group's largest infrastructure project, the $4.1 billion Airport Link.

"Staff are currently undertaking activities to protect project works and plant and equipment, however we expect that a number of offices and some sections of the project will suffer inundation over the next 24 hours," Mr Stewart said.

"To date the central part of the project, located at Kedron and Toombul, has been the main area impacted by the wet weather.

"Kedron Brook (which has been subject to flooding in recent weeks) is not expected to be affected by the combination of high tides and releases of water from Wivenhoe Dam that is currently flooding the Brisbane River, however future heavy rain in the Kedron Brook catchment area could alter this situation.

"At the Bowen Hills end of the project near Breakfast Creek and the Brisbane River, a new levee is being constructed to a height that is expected to protect tunnel works in that area. The project team has also removed any significant equipment from the tunnel at that part of the site as a precautionary measure," he said.

The extreme weather events unfolding in Queensland are unprecedented and widespread. Any material impact to Leighton Holdings' full year earnings will be determined over the coming weeks and reported once known, Leighton said.