Soil Conditions in Santa Ana
Orange County presents a range of subsurface conditions. Here's what we encounter most frequently.
Deep Alluvial Deposits
Santa Ana is situated on thick Quaternary alluvial deposits from the Santa Ana River system. These deposits consist of interbedded sands, silty sands, and clays extending to significant depth, generally providing adequate bearing capacity for conventional shallow foundations.
Historical Agricultural Fill
As one of the oldest cities in Orange County, portions of Santa Ana contain fill soils from former agricultural operations including citrus groves and walnut orchards. These fills are often undocumented, loosely placed, and may contain organic material that is compressible and unsuitable for foundation support without remediation.
Clay Layers and Expansion Potential
Clay-rich horizons within the alluvial sequence are common throughout Santa Ana. These clays can have expansion indices ranging from 40 to 80, requiring appropriate foundation design. Areas near the civic center and older neighborhoods frequently encounter near-surface clays with moderate to high plasticity.
What We Do in Santa Ana
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
WQMP preparation, LID 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 Santa Ana
ADU / Accessory Dwelling Unit
Soils reports and foundation recommendations for ADU construction on existing residential lots throughout Santa Ana's neighborhoods.
Infill Residential Development
Geotechnical and civil engineering for small-lot subdivisions and multi-family infill projects replacing older single-family homes.
Commercial Redevelopment
Site investigation and grading design for commercial and mixed-use redevelopment along major corridors such as Bristol Street and Main Street.
Industrial / Warehouse
Foundation engineering and site grading for warehouse and light industrial projects in Santa Ana's industrial districts.
Working With City of Santa Ana Planning and Building Agency
Santa Ana's Planning and Building Agency handles all grading and building permit reviews. Geotechnical reports are reviewed by the agency's engineering staff or a third-party geotechnical consultant. The agency requires complete plan sets including grading plans, soils reports, and WQMP documents submitted together for coordinated review.
What Makes This Jurisdiction Distinct
Liquefaction analysis required for projects within state-mapped liquefaction zones covering much of the city
WQMP required per Santa Ana Regional Water Quality Control Board MS4 permit standards
Grading permits require erosion control plans and compliance with the city's grading ordinance
Older sites may require Phase I Environmental Site Assessments due to historical agricultural and industrial land use
Street improvement plans required for projects fronting substandard public rights-of-way
Santa Ana accepts plan submittals through its online permitting portal. The agency offers counter appointments for plan check questions and corrections. Projects involving demolition of structures built before 1978 must address lead and asbestos abatement requirements.
Common Questions — Santa Ana
Building in Santa Ana?
Tell us about your project and we'll send you a fixed-fee proposal — typically within one business day.