Soil Conditions in Fontana
San Bernardino County sits at the transition from coastal influence to high desert — creating a wide range of soil conditions and seismic considerations. Here's what we typically find.
Lytle Creek and Cajon Creek Alluvial Fans
Fontana is situated on alluvial fan deposits from Lytle Creek and Cajon Creek. Near the fan apexes, soils are gravelly and coarse-grained with high bearing capacity. Further from the fans, deposits transition to finer-grained silty sands and clays with lower strength and higher compressibility.
Variable Fill from Agricultural History
Fontana's history as a citrus and steel production center means many sites contain variable fill material from orchard clearing, demolition, and industrial operations. Uncontrolled fill can cause differential settlement under new foundations and must be removed or recompacted before construction.
San Jacinto Fault Zone
The San Jacinto fault zone, one of the most seismically active fault systems in Southern California, passes through the eastern portion of Fontana. Seismic design parameters are high across the city, and parcels near the fault trace may require Alquist-Priolo fault rupture investigations.
Expansive and Corrosive Soil Conditions
The finer-grained soils in Fontana's lowland areas can exhibit moderate expansion potential and elevated sulfate concentrations. Expansion index testing and corrosivity testing are standard components of geotechnical investigations to determine appropriate foundation design and concrete mix specifications.
What We Do in Fontana
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 and BMP design for stormwater compliance.
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 Fontana
Warehouse & Distribution Centers
Fontana has seen extensive warehouse and logistics facility construction along I-10 and I-15 corridors. These projects require geotechnical investigation for large mat or spread footings, heavy-duty slab-on-grade design, and industrial pavement sections.
Residential Tract Development
Single-family home tracts on former agricultural land, requiring mass grading, lot-specific geotechnical recommendations, and removal or recompaction of existing fill.
Multi-Family Housing
Apartment and townhome developments driven by population growth, requiring geotechnical investigation, grading plans, and stormwater compliance packages.
ADU / Accessory Dwelling Unit
Detached ADUs and garage conversions on existing residential parcels, typically requiring a soils report for new foundation design.
Commercial & Retail
Retail centers and pad sites along Sierra Avenue, Foothill Boulevard, and Cherry Avenue, requiring standard geotechnical and civil engineering packages.
Working With City of Fontana Community Development Department
Fontana requires geotechnical investigations for new construction, grading permits, and significant additions. The Community Development department processes a high volume of submittals driven by rapid industrial and residential growth. Well-organized submittals with all required supporting documents help maintain reasonable review timelines.
What Makes This Jurisdiction Distinct
San Jacinto fault zone — Alquist-Priolo investigation required for parcels near the mapped fault trace
Geotechnical report must address potential for variable fill on former agricultural and industrial sites
Corrosivity testing required for foundation concrete and buried utilities — sulfate exposure classification per ACI 318
Large industrial projects require pavement section design and slab-on-grade recommendations for heavy floor loads and forklift traffic
Fontana's high development volume means plan check queues can fluctuate. Pre-application meetings with Community Development are recommended for large industrial projects to confirm submittal requirements and avoid incomplete application delays.
Common Questions — Fontana
Building in Fontana?
Tell us about your project and we'll send you a fixed-fee proposal — typically within one business day.