Desert View Drive Slope Repair and Restoration Project

San Diego initiated the Desert View Drive Slope Repair and Restoration in March, 2015 after observed movement on the active Rose Canyon Fault in the geologically and environmentally sensitive La Jolla area below Desert View Drive. A declaration of emergency was made due to El Niño concerns and the over 50-foot deep saturated canyon below the Mount Soledad subdivision that had seen four previous landslides since 1961 with similar indications of land movement. Repairs were analyzed, designed and substantially completed by the end of 2015. Construction involved: remote-area borings, over 25,000 yards of imported fill, storm drain realignment, permitting, and revegetation. The project total cost is $7,500,000. Construction was completed in August 2016. The project team deployed the best management techniques to complete the project on schedule, budget, and comply with the resource agency requirements and permits. We installed 6 inclinometers in the street, 150 ft deep in the ground to monitor any ground movement. Inclinometers were tied to remote observation points to monitor movement. Weekly meetings were held with the project team from beginning to end. An alternatives matrix was used to guide decision-making on independent issues. Large diameter borings for manned entry and geologic logging up to hundreds of feet deep were used to characterize movement. Construction was phased to isolate the impact area to reduce slide risk — storm drain bypass, then realignment, then canyon fill, then revegetation. Environmental specialists worked with the agencies to coordinate post-construction permitting and establish monitoring. Hauling was designed to minimize freeway lane closures and distances. The main enhancement is public safety for Mount Soledad area residents and travelers on the road and I-5 freeway. Many landslides happened in the area before. Public inconvenience, safety provision to protect public lives and property, provision of observation areas, guided tours, and means of improving relations between the city and the public. Legal challenges included inaccessible easement. The access point with the least impact was determined to be from the I-5 Freeway. Freeway access required shoulder and lane closures, night work, and avoidance of rain days. Permanent and temporary construction easements across private properties were required. The City project team were adept at managing community communication, which inspired resident cooperation. This project implied innovative techniques in management, processes, and materials. Fill was designed with select material below an agronomic soil cap to provide slope stability and supportable plant environment for revegetation. The team developed a solution to collect surface flow and avoid concrete ditches, as the city determined there is a legal issue with building and maintaining permanent improvements on private land. Cobble swales were used instead as a natural method of repair with minimized maintenanc