Caltrans will begin closing the southbound side of the 5 Freeway near Castaic for overnight repairs beginning Monday night.

The roadway was damaged in late March during a series of heavy storms, in which the hillside gave way leading to several lanes having to be closed. The freeway has been reduced to two lanes ever since the mudslide.

Beginning at 10 p.m. Monday, Caltrans will close the entire southbound side of the freeway overnight for emergency repairs.

The repairs are expected to take place each night through Thursday and again on Saturday, although Caltrans hopes to have some lanes reopened overnight before the weekend.

During the week, construction will stop and the road will reopen to traffic each morning at 5 a.m. On Saturday, the road will close at midnight and remain closed until 8 a.m. Sunday.

A detour will be in place utilizing Highway 138 and Highway 14.

“The Quail Lake Road, Smokey Bear Road, Vista Del Lago Road on-ramps and westbound State Route 138 connector to Southbound 1-5 also will be closed,” Caltrans said in a news release.

The construction schedule is subject to change and dependent on the latest weather conditions.

The northbound side of the 5 Freeway is unaffected by these repairs and motorists are urged to plan ahead and take extra precaution while construction crews are working.

The latest highway closures can be found online or by calling 1-800-427-7623.