Erosion Control: Altadena vs Castaic
How do erosion control rules compare between Altadena, CA and Castaic, CA?
Altadena and Castaic have similar restriction levels.
Altadena, CA
Los Angeles County
All grading and disturbed sites in Altadena must implement erosion controls under LA County Building Code Title 26 Appendix J and the County's MS4 permit. Rainy-season grading (Oct 15 – Apr 15) requires Best Management Practices approved by Public Works.
View full Altadena rules →Castaic, CA
Los Angeles County
Construction in unincorporated LA County must implement erosion control BMPs per NPDES stormwater permits. Projects over 1 acre require a SWPPP. The county's diverse terrain (mountains, hillsides, coastal bluffs) makes erosion control critical. Grading permits include erosion control requirements.
View full Castaic rules →Key Facts Comparison
| Fact | Altadena | Castaic |
|---|---|---|
| Code Section | LA County Title 26 App. J + CSD 22.306.060.B.3.b | - |
| Rainy Season | Oct 15 – Apr 15 | Oct 15-Apr 15 special measures |
| BMPs Required | Silt fences, fiber rolls, hydroseed | - |
| SWPPP | - | Required for sites over 1 acre |
| BMPs | - | Silt fences, fiber rolls, etc. |
| Hillside Areas | - | Enhanced requirements |
Highlighted rows indicate differences between cities.
Altadena FAQ
Do I need erosion controls during winter construction in Altadena?
Yes — rainy-season grading (Oct 15 to Apr 15) must implement Public Works–approved BMPs per Altadena CSD 22.306.060.B.3.b.
Castaic FAQ
What erosion controls are required for construction in LA County?
All projects disturbing soil must use BMPs such as silt fences, fiber rolls, and stabilized entrances. Projects over 1 acre need a SWPPP. Requirements are heightened during rainy season (October 1 - April 15).
Do I need a grading permit for erosion-prone work?
Yes. Grading permits from LA County Building & Safety include erosion control requirements. Even exempt grading work must implement basic BMPs to prevent sediment discharge.
What happens if sediment runs off my construction site?
Sediment discharge can result in county fines up to $10,000/day and separate penalties from the Regional Water Quality Control Board. You may also face stop-work orders until controls are installed. Report discharges to (888) 846-0800.
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