Alta Vista Pipeline - Montara, CA

Client: City of Montara
Consultant: Kleinfelder Inc. and Olivia Chen
Main Contractor: Granite Construction

Project Specification:

The Alta Vista pipeline is over 100 years old. It is the main water source for the City of Montara, located 10 miles north of Half Moon Bay, on the Pacific coast. This Pristine Coastal Area falls under the jurisdiction of the Coastal Commission, Water Board and the California Department of Fish and Game. The pipeline sits on a steep slope which rises 30' and has a history of instability and ground movement. Due to its age, the pipeline was falling apart and needed to be replaced. Initial proposals to replace the pipeline also included the construction of two geosynthetic reinforced walls for repairing the slope. These walls were rejected by the authorities due to the requirement of heavy installation equipment, environmental disturbance and potential impact on local wildlife.


Kleinfelder Inc., Biological Consultant, and Olivia Chen, Civil Engineering Consultant, re-designed the slope repair using The Platipus® Anchored Reinforced Grid Solution(ARGS®) because it was low impact, required only hand held equipment for installation and provided an instantly attractive finish to the slope. It also meant that permits, that had proved so difficult to obtain from the authorities, were no longer required. The S6 ARGS® Percussive Driven Earth Anchors (PDEAs®) were driven through High Performance Turf Reinforcement Matting (HPTRM), on a checkerboard grid pattern, stabilizing the slope and preventing the risk of future erosion. The contractor, Granite Construction of Wastonville, CA, was particularly impressed with the speed and simplicity of the Platipus® ARGS® completing the entire installation in just two days.

For more information

Get in touch