Stormwater Management: Altadena vs El Monte
How do stormwater management rules compare between Altadena, CA and El Monte, CA?
Altadena and El Monte 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 →El Monte, CA
Los Angeles County
El Monte is developing a Stormwater Urban Master Plan to improve water quality. The city participates in the LA County MS4 NPDES permit. New development must implement BMPs. Report illicit discharges to Public Works at (626) 580-2250.
View full El Monte rules →Key Facts Comparison
| Fact | Altadena | El Monte |
|---|---|---|
| Authority | LA County Code Title 12 + State Water Board MS4 | - |
| Construction SWPPP | Required ≥1 acre disturbance | - |
| Illicit Discharge Hotline | (888) CLEAN-LA | - |
| Permit | - | LA County MS4 NPDES |
| Master Plan | - | Stormwater Urban Master Plan |
| Report | - | Public Works (626) 580-2250 |
| BMPs | - | Required for new development |
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.
El Monte 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 El Monte public works.
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