Soil Conditions in National City
San Diego's geology varies dramatically from neighborhood to neighborhood. Here's what we see most often.
Bay-Margin Deposits
Western National City near the waterfront contains soft bay clays and marine-influenced deposits. These soils have low bearing capacity and high compressibility, potentially requiring deep foundations or ground improvement for heavier structures.
Lindavista Formation Terrace
The elevated portions of National City sit on Lindavista Formation terrace deposits — firm sandy clay with moderate expansion potential. These soils generally provide adequate bearing for conventional foundations with standard expansive soil mitigation.
Sweetwater River Alluvium
The southern boundary along the Sweetwater River contains alluvial sands and silts with shallow groundwater. Liquefaction analysis is required for sites within the mapped seismic hazard zone near the river.
What We Do in National City
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 compliance, WQMP preparation, 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 National City
ADU / Accessory Dwelling Unit
ADU construction on National City's compact residential lots. Soils reports are required for new detached structures.
Single-Family Home
Infill and replacement home construction throughout National City's residential neighborhoods.
Commercial Redevelopment
Commercial and mixed-use redevelopment projects, often on sites with historical fill or industrial use.
Working With City of National City Building Department
National City requires geotechnical investigations for most new construction. Reports are submitted with building permit applications and reviewed by city staff.
What Makes This Jurisdiction Distinct
Bay-adjacent properties may require environmental phase assessment in addition to geotechnical work
Liquefaction analysis required for sites in mapped seismic hazard zones
Compact lot sizes may require specialized drilling access considerations
Stormwater compliance per San Diego Regional MS4 permit
Submit to the Building Department at National City City Hall, 1243 National City Boulevard.
Common Questions — National City
Building in National City?
Tell us about your project and we'll send you a fixed-fee proposal — typically within one business day.