State Route 150 Landslide Recovery Plan
Overview
The California Department of Transportation (Caltrans) and emergency contractors are working as quickly as possible to stabilize and clear a large landslide that closed State Route 150 north of Santa Paula in Ventura County in February 2024.
Due to delays in procurement in materials, Caltrans anticipates one lane on this section of Route 150 could open to traffic by the end of July 2024. This is only a target date and subject to change due to weather and other conditions beyond the control of Caltrans.
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. A detour for motorists is available through the cities of Ventura and Ojai using State Route 126, U.S. Highway 101, and State Route 33.
Through traffic on Route 150 is blocked between Stonegate Road in Santa Paula, south of the slide, and Mupu Road at Steckel Park, north of the slide. Limited local access is 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
Landslide on State Route 150 - "Not your typical slide"
Question: "Why isn't Caltrans removing the slide now?"
Answer: Recent powerful rainstorms saturating the hillside appear to be the primary cause of the landslide. Water can be seen seeping out of the hillside and ponding within the slide, ponding which Caltrans is pumping to remove. Caltrans is very concerned regarding further landslide activity (within the active zone and adjacent hillsides) if debris is removed from the road.
Working on a swift timetable, Caltrans developed geotechnical recommendations and design for a retaining wall to stabilize the area. Because of the sensitive geologic nature of the site, the design must be precise to ensure the safety of the area.
The final geotechnical recommendations laboratory testing of core samples that were obtained by drilling at five locations, completed on March 11, 2024. The lab tests were submitted to three different laboratories for accelerated testing since there is limited testing equipment available at each laboratory. Slope analysis and geotechnical recommendations were expedited due to the high priority to reopen State Route 150 as soon as possible.
Caltrans engineers refined their model within two days of receiving the laboratory test results to provide the necessary geotechnical recommendations and retaining wall plans. In addition, the laboratory test results will also be used to analyze whether more than one retaining wall is necessary.
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. In the meantime, Caltrans has been working intensively to find short-term solutions to meet local transportation needs, such as a pedestrian path, a local bypass route for vehicles, and a shuttle bus service to transport students, workers, and others around the slide. The start of free shuttle bus service was announced March 18 by the Ventura County Transportation Commission in cooperation with Caltrans.
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 ais 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: "How can I get information on the shuttle service?"
A: The Ventura County Transportation is providing a free emergency shuttle service between Santa Paula and Ojai to help residents affected by the closure of State Route 150. Children 5 and younger must be accompanied by an adult. For more information on the shuttle service, visit: https://www.goventura.org/sr150/
Q: "Why hasn't Caltrans built a pedestrian path around the slide?"
A: A pedestrian path is now open between the hours of 6 a.m. and 8 p.m.
Signage is posted since the path is on private property and will state the following:
"CAUTION: YOU ARE ABOUT TO ENTER A NON-ADA COMPLIANT EMERGENCY PEDESTRIAN TRAIL ON PRIVATE PROPERTY. THERE WILL BE HANDRAILS AND CARVED STEPS TO GUIDE YOU THROUGH - PLEASE BE CAREFUL. THE TRAIL IS PROVIDED FOR THE CONVENIENCE OF THE COMMUNITY. BE RESPECTFUL TO THE PROPERTY OWNER - DO NOT LITTER NOR LINGER. THANK YOU FOR YOUR COOPERATION."
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 confident that the road will be open well before fire season and 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. Crews have constructed a temporary access road for construction equipment that will be available to first responders.
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.
Q: "How can I get my mail delivered?"
A: For issues with mail, reach out to your U.S. Representative so they can explain the available options for mail delivery:
• Request a Free temporary mailbox installed outside of the Santa Paula Post Office.
• Request General Mail Delivery and have your mail forwarded to the Ojai Post Office available for pick up.
• Have your mail forwarded from Santa Paula to a PO box at the Ojai Post Office. You will need to purchase a P.O. Box if you don't already have one: https://www.usps.com/manage/po-boxes.htm.