Stormwater Management: Altadena vs Torrance
How do stormwater management rules compare between Altadena, CA and Torrance, CA?
Altadena and Torrance have similar restriction levels.
Altadena, CA
Los Angeles County
LA County operates under a regional MS4 permit issued by the LA Regional Water Quality Control Board. LA County Code Title 12 prohibits discharging non-stormwater (sediment, chemicals, paint, sewage, washwater) into storm drains.
View full Altadena rules →Torrance, CA
Los Angeles County
Torrance enforces LA County MS4 stormwater permit requirements. New development must incorporate Low Impact Development features to manage runoff.
View full Torrance rules →Key Facts Comparison
| Fact | Altadena | Torrance |
|---|---|---|
| Authority | LA County Code Title 12 + State Water Board MS4 | - |
| Construction SWPPP | Required ≥1 acre disturbance | - |
| Illicit Discharge Hotline | (888) CLEAN-LA | - |
| MS4 Permit | - | LA County requirements apply |
| LID | - | Required for new development |
| Construction | - | BMP required during building |
| Illicit Discharge | - | Prohibited to storm drains |
Highlighted rows indicate differences between cities.
Altadena FAQ
Can I hose my driveway into the gutter in Altadena?
Generally no — soapy or sediment-laden runoff into the storm drain violates the LA County NPDES MS4 permit and Title 12.
Torrance FAQ
Do I need a stormwater plan for my project?
Generally required for new construction and major renovations that increase impervious surface area. Small residential projects may be exempt.
What is an illicit discharge?
Any non-stormwater substance entering the storm drain system, including paint, oil, chemicals, or sediment. Report violations to Torrance public works.
Compare other topics
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