Falling debris has forced the closure of Highway 1 at Alder Creek again in both directions — the same section that had reopened just a week ago after a mudslide last month.

Caltrans said Friday that the area continues to be extremely unstable, and that the section is likely to be closed for at least a month.

Alder Creek is south of Nacimiento-Fergusson Road, which is open as an alternate route into Big Sur. Caltrans and the California Highway Patrol advise against unnecessary travel in the area, especially at night.

Another stretch of Highway 1, at Rocky Creek, which has been closed after mudslides took out large portions of the cliffside lane, will open for all traffic — without any weight or length restrictions — from 5 p.m. Saturday to 8 a.m. Sunday. That section of Highway 1 then will open each night from 8 p.m. to 8 a.m.

One-way reversing traffic control will be in effect. This will continue until all temporary repairs at Rocky Creek are finished. Work is scheduled to be completed the first week of May.

Construction crews are continuing to drill in soil nails and to stabilize the newly eroded area. Bus service is available from Monterey-Salinas Transit into the Monterey area.

Noozhawk staff writer Giana Magnoli can be reached at gmagnoli@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk or @NoozhawkNews.