State Route 150 Landslide Recovery Plan
Overview
The California Department of Transportation (Caltrans) and emergency contractors are working to stabilize and clear a large landslide that closed State Route 150 north of Santa Paula in Ventura County from February 2024 to July 31, 2024.
Since July 31, State Route 150 is open to traffic in both directions at the location of the landslide near Bridge Road.
Work is still ongoing, and occasionally there will be a one-lane closure to facilitate the remainder of the construction. During these one-lane closures, flaggers will be on site directing traffic, and motorists should allow extra travel time and anticipate a short delay. Closures will be avoided during peak travel times from 7 a.m. to 9 a.m. and 4 p.m. to 6 p.m.
Conditions in the construction zone
· At least one lane will be open for traffic at all times. There are no plans for full closures (all lanes) on State Route 150.
· The southbound and northbound shoulders are closed.
· The speed limit in the work zone is 25 mph.
· A pedestrian path through private property remains open until further assessment.
· The Ventura County Transportation Commission (VCTC) has ceased operating its shuttle that took passengers on a detour around the slide via Routes 126, 101 and 33.
· In the work zone, crews are continuing to remove dirt and material on SR 150, constructing the large retaining wall, final grading and landscaping for erosion control.
Project Background
A community update was held on April 30, 2024 and can be viewed on the Caltrans District 7 YouTube page.
Project Impact
The slide occurred during powerful storms that saturated the region. The area of the slide is approximately 1.8 acres. The approximate dimensions from the head scarp to the toe is 750 feet and it ranges in width from 100 feet to 200 feet. This part of Route 150 is used by more than 3,200 vehicles a day, on average.
No roads are available nearby to serve as a local detour in the rural area. During the full closure of Route 150, a detour for motorists was available through the cities of Ventura and Ojai using State Route 126, U.S. Highway 101, and State Route 33.
During the full closure, through traffic on Route 150 was blocked between Stonegate Road in Santa Paula, south of the slide, and Mupu Road at Steckel Park, north of the slide. Limited local access was allowed in the closed area.
The large, unstable landslide, which took place on February 21, 2024, is located just north of the city of Santa Paula at Bridge Road (postmile 31.4), about three miles north of State Route 126.
After multiple soil tests were conducted, Caltrans chose to build a soldier pile retaining wall which is currently in construction.
Frequently Asked Questions (FAQ) as of March 19, 2024
Q: "Isn't it a simple job to push the material off the road?"
A: The hillside consists of multiple nested slides, which have moved in the past leaving exposed visible exposed scarps. The slide movement in February deposited slide debris on State Route 150, debris which is currently acting as a temporary buttress to support the material uphill, both vertically and laterally. More slides could occur if material is removed from Route 150. Caltrans is closely monitoring the active slide and the adjacent areas for additional slope movement.
Caltrans also hired a to install a system that detects further movements in the slide during construction.
Q: "Why isn't Caltrans moving faster to start this process?"
A: Actually, Caltrans started this complex investigation process immediately after the slide occurred. Caltrans secured the area and monitored the slide for further movement, and Caltrans continues monitoring it closely. Caltrans immediately developed a plan of action for reopening Route 150 as quickly as possible. Caltrans informed motorists, the community, local leaders, elected officials, and others regarding this emergency and what's ahead, with close coordination among agencies at the local, state, and federal levels to respond to the community's needs. Also, Caltrans immediately started the geotechnical investigation of the slide area. Caltrans quickly arranged an emergency contractor to provide additional equipment and workers. Caltrans assembled teams of experts in design, construction, and emergency operations for an all-hands-on-deck, expedited response to this event.
Q: "Why can't Caltrans complete this process in a week or two?"
A: Safety is the top priority of Caltrans. Caltrans is committed to opening State Route 150 as soon as it can be accomplished safely.
Caltrans designed the project and has completed a set of plans. While the designs and reviews were ongoing, Caltrans sourced all the material that we will need to complete the project including beams, wood lagging, fabrication shops, etc.
The estimated length of the retaining wall needed to support this slide is to be up to 360 feet in length with a height of 40 to 50 feet. Multiple rows of ground anchors extending up to 200 feet in length will be constructed through the face of the wall and extend through the slide plane for anchoring the wall. The face of the wall will be buried up to a certain depth which is still to be determined. Considerations, monitoring and analysis will be performed by Caltrans engineers and geologists to determine whether State Route 150 can be opened during partial construction of the retaining wall.
Q: "There are issues on elsewhere on State Route 150 near Dennison Grade where material has come down a slope, and near Thomas Aquinas College due to a slip-out. Is it safe to drive near those locations? What is being done about those issues?"
A: It is safe for motorists to drive these sections of State Route 150. Caltrans crews are closely monitoring Dennison Grade and removing any materials that can pose a hazard to motorists and cyclists. The slip-out about one-fourth of a mile south of Thomas Aquinas College has been repaired.
Q: "Residents are concerned about potential wildfires and evacuation routes in case of an emergency. What will be done about this?"
A: Caltrans is coordinating the status of repairs with partner agencies such as the Ventura County Fire Department. In case of any emergency, Caltrans recommends having a plan in place if any evacuation is needed and to follow any orders from public safety personnel for the region.
Q: "Are there any issues with funding for this emergency project?"
A: There are no issues with funding for the slide removal and the repairs that will be necessary to reopen State Route 150.
Q: "How can I be informed of updates for the reopening of State Route 150?"
A: You can e-mail SR150Slide@dot.ca.gov
Q: "Who is the contractor for this emergency project?"
A: The contractor is R&R Demo and Grading Corp. of Woodland Hills (Los Angeles), California.