Stormwater Management: Oxnard vs Simi Valley
How do stormwater management rules compare between Oxnard, CA and Simi Valley, CA?
Simi Valley has fewer restrictions than Oxnard.
Oxnard, CA
Ventura County
Oxnard enforces stormwater pollution prevention under its NPDES Municipal Separate Storm Sewer System (MS4) permit. Construction sites, commercial properties, and industrial operations must prevent pollutant discharge to storm drains flowing to the Pacific Ocean.
View full Oxnard rules →Simi Valley, CA
Ventura County
Simi Valley enforces stormwater management regulations under the Ventura County Municipal Separate Storm Sewer System (MS4) permit. Construction projects must implement best management practices to prevent pollutants from entering storm drains.
View full Simi Valley rules →Key Facts Comparison
| Fact | Oxnard | Simi Valley |
|---|---|---|
| Permit | Ventura County MS4 NPDES | - |
| SWPPP Required | For sites 1+ acre disturbed | For qualifying construction projects |
| LID Required | New development must include | New development post-construction |
| Penalty | Up to $10,000 per day | - |
| Permit Trigger | - | 1+ acre disturbance needs CGP |
| Storm Drain Discharge | - | Non-stormwater prohibited |
Highlighted rows indicate differences between cities.
Oxnard FAQ
What are Oxnard's stormwater rules?
Oxnard prohibits pollutant discharge to storm drains under its NPDES MS4 permit. Construction sites over one acre need SWPPPs. New developments must include Low Impact Development measures.
Where does Oxnard stormwater go?
Oxnard's storm drains flow directly to the Pacific Ocean through channels including the Oxnard Industrial Drain and Santa Clara River estuary. No treatment occurs, making pollution prevention critical.
Do I need a stormwater plan for my construction project?
If your project disturbs one acre or more, you need a SWPPP and General Construction Permit coverage. Smaller projects may still need Best Management Practices per city requirements.
Simi Valley FAQ
Do I need a stormwater plan for my construction project?
Projects disturbing one acre or more need a Construction General Permit and SWPPP. Smaller projects still must implement erosion and sediment control BMPs during construction.
Can I wash my car in the driveway?
Car washing on pervious surfaces that absorbs runoff is generally acceptable. Wash water should not flow into storm drains. Use a commercial car wash or wash on a lawn where water can infiltrate.
What is LID and does it affect my project?
Low Impact Development requires new construction to manage stormwater on-site through features like permeable pavement, rain gardens, or infiltration. It applies to new development and significant remodels.
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