Grading & Drainage: Oxnard vs Simi Valley
How do grading & drainage rules compare between Oxnard, CA and Simi Valley, CA?
Oxnard and Simi Valley have similar restriction levels.
Oxnard, CA
Ventura County
Oxnard requires grading permits for earthwork exceeding specified thresholds. The flat topography of the Oxnard Plain requires careful drainage design to prevent flooding, particularly near the Santa Clara River floodplain and coastal areas.
View full Oxnard rules →Simi Valley, CA
Ventura County
Simi Valley requires grading permits for significant earth-moving activities and enforces drainage standards to prevent erosion, sedimentation, and impacts on neighboring properties. Hillside grading is subject to enhanced review.
View full Simi Valley rules →Key Facts Comparison
| Fact | Oxnard | Simi Valley |
|---|---|---|
| Permit Threshold | Over 50 cubic yards | - |
| Engineering | Licensed civil engineer required | - |
| Drainage | Must direct away from structures | May not impact neighboring properties |
| Flood Zone | FEMA compliance near Santa Clara River | - |
| Permit Trigger | - | Over 50 cubic yards cut/fill |
| Hillside Grading | - | Geotechnical report required |
| Erosion Control | - | Required October through April |
Highlighted rows indicate differences between cities.
Oxnard FAQ
When do I need a grading permit in Oxnard?
Grading permits are required for earthwork exceeding 50 cubic yards or any work that alters drainage patterns on your property. Contact Building Division at (805) 385-7858.
Why is drainage design important in Oxnard?
Oxnard's flat terrain and high water table make drainage critical. Poor drainage can cause flooding, especially near the Santa Clara River floodplain and coastal low-lying areas.
Can I change drainage on my Oxnard property?
Any changes affecting drainage patterns require a grading permit. You cannot redirect water flow onto neighboring properties. An engineer must design proper drainage solutions.
Simi Valley FAQ
Do I need a grading permit in Simi Valley?
Yes, for earth-moving exceeding 50 cubic yards. Projects on steep slopes or in hillside areas require geotechnical reports and enhanced review by the Building Division.
Can I change the drainage on my property?
Grading may not direct water onto neighboring properties. A drainage study may be required for projects that significantly alter surface water flow patterns.
When are erosion controls required?
Temporary erosion control measures must be in place during the rainy season (October through April) and throughout active construction regardless of season.
Compare other topics
See how Oxnard and Simi Valley compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool