Calero Valve Yard Geotechnical Borings and Utility Potholing

The Santa Clara Valley Water District is initiating a project in San Jose, California, to support the final design of the Calero Dam Seismic Retrofit Project. The scope of work consists of two primary components: collecting geotechnical data to inform the construction of a sheet pile wall for flood protection at the Calero Valve Yard and performing utility potholing to locate underground utilities. Geotechnical activities include drilling three borings up to 25 feet deep using a truck mounted drill rig with hollow stem augering and excavating a 100 foot trench. Potholing involves using a hydrovac truck to excavate approximately four potholes along the Almaden Valley Pipeline near Calero Reservoir to determine the concrete encasement configuration for a valve vault box relocation. The project is estimated to take approximately six days to complete and will disturb about 1500 square feet of ruderal vegetation. All borings must be backfilled with a cement bentonite grout mixture according to Valley Water Well Ordinance Program standards, while pothole excavations must be backfilled with native material and compacted. This project is classified under NAICS code 541360 and is managed by Associate Environmental Planner Abby Annicchiarico. Under the California Environmental Quality Act, the project qualifies for categorical exemptions due to the minor nature of the land alterations and the basic data collection involved.