Erosion Control: Altadena vs Carson
How do erosion control rules compare between Altadena, CA and Carson, CA?
Altadena and Carson 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 →Carson, CA
Los Angeles County
Carson does not have a standalone erosion-control chapter; erosion and sediment control are enforced through the city's adoption of California Building Code Appendix J (Grading) under its Building Code, the city's Storm Water and Urban Runoff Pollution Control Ordinance (CMC Art. 4 Ch. 8), and the state Construction General Permit. Carson's mostly flat terrain limits hillside-style erosion exposure, but construction sites must still implement Best Management Practices to prevent sediment from entering the MS4 and the Dominguez Channel.
View full Carson rules →Key Facts Comparison
| Fact | Altadena | Carson |
|---|---|---|
| Code Section | LA County Title 26 App. J + CSD 22.306.060.B.3.b | - |
| Rainy Season | Oct 15 – Apr 15 | - |
| BMPs Required | Silt fences, fiber rolls, hydroseed | - |
| Local citation | - | Carson Building Code (CMC Art. 8) adopting CBC Appendix J (Grading) |
| Stormwater overlay | - | Carson Municipal Code Art. 4 Ch. 8 (Storm Water and Urban Runoff Pollution Control) |
| State permit threshold | - | ≥1 acre disturbed area → Construction General Permit (Order 2022-0057-DWQ) + SWPPP |
| BMP basics | - | Silt fence, fiber rolls, stabilized entrance, inlet protection, hydroseed, concrete washout containment |
| Topography | - | Mostly flat South Bay coastal plain — wind erosion + channel-edge sediment are key risks |
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.
Carson FAQ
Does my small backyard project need erosion controls?
Yes, even projects under 1 acre must keep sediment and construction debris out of the storm drain under CMC Art. 4 Ch. 8. Practical measures include placing soil piles away from streets, covering stockpiles, sweeping (not hosing) sidewalks, and using fiber rolls along curbs during grading.
What triggers a SWPPP in Carson?
Disturbing 1 acre or more (cumulatively, including phased projects) triggers the state Construction General Permit, requiring electronic Notice of Intent in SMARTS and a Stormwater Pollution Prevention Plan prepared by a Qualified SWPPP Developer (QSD).
Is Carson considered a hillside community for grading purposes?
No. Carson is on flat South Bay coastal plain at roughly 20-50 feet elevation; CBC Appendix J's hillside-specific provisions rarely apply, but grading-permit requirements still apply to any project moving more than 50 cubic yards of earth or creating slopes that affect drainage.
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