Soil Conditions in Torrance
Los Angeles County's geology is as varied as its neighborhoods. Here's what we typically find.
Marine Terrace Deposits
Torrance sits on uplifted Pleistocene marine terrace deposits consisting of dense sands and stiff to hard clays. These older deposits generally provide good bearing capacity for conventional foundations, though lateral variation in soil type and density is common across the terraces.
Palos Verdes Sand and Older Alluvium
The western portion of Torrance near the Palos Verdes Peninsula is underlain by Palos Verdes Sand and older alluvium. Expansive clay soils derived from weathered bedrock are found in some areas and can cause foundation distress if not properly accounted for in the geotechnical design.
Shallow Groundwater
Groundwater in parts of Torrance, especially in the lower-lying areas near the Dominguez Channel and Torrance Lateral, is encountered at relatively shallow depths. Shallow groundwater influences foundation design, requires dewatering consideration for subterranean construction, and contributes to liquefaction susceptibility.
Newport-Inglewood Fault Proximity
The Newport-Inglewood fault zone lies to the east of Torrance. While most of Torrance proper is outside the Alquist-Priolo zone, the proximity of this active fault system means seismic design considerations are important. Some eastern Torrance properties may fall within liquefaction hazard zones.
What We Do in Torrance
Soils Reports
Geotechnical investigation and foundation recommendations for building permits.
Learn more →Grading Plans
Precise and rough grading design with drainage and earthwork calculations.
Learn more →Compaction Testing
Field density testing and fill certification for construction.
Learn more →Stormwater / LID / WQMP
LID/WQMP compliance and BMP design.
Learn more →Hydrology Reports
Drainage analysis and flood risk assessment.
Learn more →Subsurface Exploration
Drilling, CPT, and test pit programs.
Learn more →Erosion Control Plans
SWPPP and erosion control for grading permits.
Learn more →Street Improvements
Frontage, curb, gutter, and sidewalk design.
Learn more →Utility Plans
Water, sewer, and storm drain design and coordination.
Learn more →Project Coordination
One point of contact managing structural, MEP, surveying, and specialty consultants.
Learn more →We also coordinate with your structural engineer, architect, MEP consultants, and other project team members to ensure our deliverables integrate with the overall design — one point of contact for your geotechnical and civil engineering scope.
What People Build in Torrance
Single-Family Home
New homes and major additions in established Torrance neighborhoods are the most common project type. The generally competent soil conditions keep foundation costs reasonable for most sites.
ADU / Accessory Dwelling Unit
ADU construction is popular in Torrance's single-family zones. A soils report is required for new detached ADUs and may be required for conversions depending on foundation modifications.
Commercial and Retail
Torrance's commercial corridors along Hawthorne Boulevard and Torrance Boulevard see ongoing renovation and new construction requiring geotechnical and civil engineering services.
Industrial / Warehouse
The industrial areas of Torrance near the refineries and Del Amo Boulevard occasionally require geotechnical investigation for new buildings or equipment foundations on sites with potential environmental considerations.
Working With City of Torrance Community Development Department
Torrance Community Development requires geotechnical investigations for new construction and significant grading. The soils report is reviewed by the city's plan check engineer as part of the building or grading permit process. Turnaround times are generally moderate compared to larger LA County jurisdictions.
What Makes This Jurisdiction Distinct
Geotechnical report required for new construction and grading permits
Expansive soil mitigation required where expansion index exceeds threshold per CBC
WQMP and LID compliance required for new development per LA County MS4 Permit
Seismic hazard zone studies required where properties fall within CGS-mapped zones
Street improvement plans required for frontage work along city right-of-way
Submit geotechnical reports and grading plans to the Community Development Department counter. Torrance uses standard LA County grading code provisions with some local amendments.
Common Questions — Torrance
Building in Torrance?
Tell us about your project and we'll send you a fixed-fee proposal — typically within one business day.