Strawberry Creek Stabilization

Berkeley, CA

University of California, Berkeley
Summer 2003

Hanford ARC was contracted by UC Berkeley to repair a landslide and stabilize a segment of Strawberry Creek in the upper part of the Botanical Garden. High flows on Strawberry Creek had undermined the toe of a steep slope, causing an approximately 40-foot tall slump. As the soil moved downhill, it deposited sediment into the stream and left a toe consisting of loose material. This situation became an ongoing problem.

Hanford ARC was contracted to reconstruct the slope and stabilize the channel bed and toe with a series of rock weirs and toe protection. The steep slopes, narrow access, and sensitive work environment (working in close quarters with specimen plants) provided many challenges. Access was provided on a single lane road to the project site, and then along a narrow footpath, lined with plants, to the actual work area.

Many protection measures were installed, including plywood barrier fencing, trench plates for rock stockpiling, and an assortment of other roping, fencing and signage. In addition, trees and shrubs were pruned or tied back by the Garden. Safety was of utmost priority as the Garden remained open during construction, and the work area was extremely steep.

Extensive clearing of brush and debris was required to prepare the site for excavation. Logs removed during this clearing, as well as eucalyptus harvested off-site, were used for the log structures.

Hanford ARC mobilized an excavator and large skid steer loader. A gravity system was setup to bypass the stream flow around the work area. A road was excavated through the middle of the slide and a platform was established at the base of the slope. The rock weirs were constructed in the channel, followed by the rock toe.

The slope was reconstructed from the base, with all soil replaced and compacted as the equipment worked up-slope. The slope was finish graded during this process and the road cut restored. Once complete, The footpath was restored, landscape rock replaced and protection measures removed.