Stormwater Management: Altadena vs Santa Clarita
How do stormwater management rules compare between Altadena, CA and Santa Clarita, CA?
Altadena and Santa Clarita 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 →Santa Clarita, CA
Los Angeles County
Santa Clarita enforces LA County MS4 stormwater permit requirements. New development must manage runoff with LID features. The Santa Clara River watershed is a key concern.
View full Santa Clarita rules →Key Facts Comparison
| Fact | Altadena | Santa Clarita |
|---|---|---|
| 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 |
| Watershed | - | Santa Clara River |
| Illicit Discharge | - | Prohibited |
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.
Santa Clarita 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 Santa Clarita public works.
Compare other topics
See how Altadena and Santa Clarita compare on other ordinance categories.
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