San Jose Excavation and Grading
San Jose doesn’t dig the same everywhere. On the flat valley floor in Willow Glen or Cambrian, a project usually means expansive clay, old fill and water that needs somewhere to go. In the hills above Almaden Valley, Evergreen and Silver Creek, the same project can bring slope stability, fault zones and a geologist’s review. Harris Excavation handles excavation, grading, drainage and trenching across San Jose for homeowners, general contractors and developers.
We’re a licensed general engineering contractor (CSLB #1117960) based in South San Francisco.
Excavation and Grading Services in San Jose
- Foundation and footing excavation for additions, ADUs and new homes, laid out with a laser for line and grade. Residential excavation
- Grading and drainage repair for yards and planters that slope toward the house. Residential drainage
- Downspout and subsurface drain lines that carry roof water to a safe outlet
- Utility trenching for water, sewer, storm and electrical lines, including PG&E service upgrades. We’re PG&E Operator Qualified. Residential trenching
- Retaining wall excavation and backfill on hillside lots
- Erosion and sediment control for sites that have to work through the wet season. Erosion control
Exempt or Not, San Jose Wants It on File
San Jose Public Works starts broad. Anyone excavating, grading, installing onsite storm drainage or building retaining walls in the city needs either a Notice of Exemption or a Grading Permit. That includes the drainage fix or low wall most people assume is too small to count.
On a flat site, a standard Grading Permit typically applies once you pass 150 cubic yards of cut or fill. To stay exempt, the work also can’t cut deeper than 2 feet or build fill taller than 3 feet, among other conditions. Basement and footing excavation can be exempt if it leaves no unsupported cut over 5 feet. Sites that slope more than 5% across the lot go through a Hillside Grading Permit instead. If a dig needs construction shoring, the City requires a separate shoring approval on top of the grading permit.
Valley Floor or Hillside: Why It Changes the Job
On the valley floor. San Jose’s General Plan geology appendix says much of the city’s soil is moderately to highly expansive, so grade and drainage matter even on flat lots. For older infill areas like Willow Glen, it flags undocumented fill, weak or saturated soils and old bay mud. Land along the Guadalupe River and Coyote Creek is most prone to lateral spreading in a quake.
In the hills. The same appendix puts most of the city’s landslide activity in the Diablo Range foothills on the east side, with less in the Santa Teresa Hills and the Santa Cruz Mountains to the southwest. For Almaden Valley it lists landslides, fault setback zones and cut and fill slope stability. The Silver Creek Fault is zoned a fault rupture hazard in the foothills. If your site is in the City Geologic Hazard Zone or the State’s seismic landslide hazard zone, Public Works requires a Geologic Hazard Clearance before it issues a grading permit, backed by review from licensed engineering geologists and geotechnical engineers.
Trees and the Wet Season
On single-family and duplex lots, removing an ordinance-size tree takes a City permit. That’s a single trunk 38 inches or more around (about 12 inches across) at 4.5 feet above the ground. On multifamily, commercial and industrial sites, any tree needs a permit. Street trees can sit up to 12 feet back from the curb.
Timing matters too. San Jose doesn’t allow grading between October 1 and April 30 without erosion control plans and measures approved by the Director of Public Works.
Recent San Jose Projects
Grading and drainage repair. A homeowner was seeing foundation settlement and cracking. We found a front planter sloped toward the house and two downspouts dumping water at the foundation corners. We regraded the planter toward the front lawn and installed a subsurface drain to carry downspout water to a safe outlet. The work took two days. Read the drainage project.
Foundation excavation for an addition. To close out 2025, we graded and compacted the foundation pad, dug the perimeter footings with laser layout to minimize formwork, and augered an 18-inch pier footing for the main floor beam. Spoils went to a regulated site. We finished on schedule and came back after equipment pickup to clean the driveway. Read the foundation project.
San Jose Neighborhoods We Serve
We work across San Jose, including Willow Glen, Rose Garden, Cambrian, Berryessa, Alum Rock, Evergreen, Silver Creek and Almaden Valley. Nearby, we also serve Santa Clara, Sunnyvale, Campbell, Cupertino and Palo Alto. See all of our Santa Clara County work.
San Jose Excavation FAQ
Do I need a grading permit to fix drainage in my yard?
You’ll need either a Notice of Exemption or a Grading Permit. We’ll review your scope and tell you which one is likely.
How do I know if my lot is in a geologic hazard zone?
Ask San Jose Public Works Development Services or your geotechnical engineer. If it is, you’ll need a Geologic Hazard Clearance before a grading permit.
Can I grade during the rainy season?
Between October 1 and April 30, only with erosion control plans and measures approved by Public Works.
Get a San Jose Excavation Estimate
Send us your plans and any soils or geologic report. We’ll walk the site and send a clear written estimate. Request a free estimate