Dark Sky Rules: Altadena vs Norwalk
How do dark sky rules rules compare between Altadena, CA and Norwalk, CA?
Altadena and Norwalk have similar restriction levels.
Altadena, CA
Los Angeles County
LA County's Rural Outdoor Lighting District (ROLD) ordinance, effective 2012, requires fully shielded outdoor lighting and prohibits light trespass in designated rural unincorporated areas. The ROLD covers mountain and rural communities. Mercury vapor lights and drop-down lenses are prohibited.
View full Altadena rules →Norwalk, CA
Los Angeles County
Norwalk regulates outdoor lighting to reduce light pollution and glare. Fully shielded fixtures required for new installations. Lighting must be directed downward and not trespass onto neighboring properties.
View full Norwalk rules →Key Facts Comparison
| Fact | Altadena | Norwalk |
|---|---|---|
| ROLD | Effective since 2012 | - |
| Shielding | All outdoor lighting must be fully shielded | - |
| Mercury Vapor | Prohibited | - |
| Applies To | Rural unincorporated areas | - |
| Fixtures | - | Fully shielded required |
| Direction | - | Downward only |
| Color Temp | - | 3000K or below preferred |
| Topic | - | Dark Sky Rules |
Highlighted rows indicate differences between cities.
Altadena FAQ
Does LA County have dark sky rules?
Yes. The Rural Outdoor Lighting District (ROLD) ordinance restricts outdoor lighting in rural unincorporated areas. It requires full shielding, warm color temperatures, and maximum lumen limits to reduce light pollution.
Am I in the ROLD?
The ROLD covers rural unincorporated communities in the Santa Monica Mountains, northern LA County, and other designated areas. Check with the Department of Regional Planning at (213) 974-6411 or review the ROLD boundary maps on planning.lacounty.gov.
What type of outdoor lights are allowed in ROLD areas?
Fully shielded fixtures (no upward light emission) with warm white color temperature (below 3000K recommended). Maximum lumen output varies by fixture type and location. All new fixtures must be ROLD-compliant.
Norwalk FAQ
What does fully shielded mean?
The fixture must direct all light downward with no light emitted above the horizontal plane. This prevents glare and sky glow while still providing ground illumination.
Can my neighbor's lights shine into my yard?
Most codes prohibit light trespass onto neighboring properties. Contact Norwalk code enforcement if outdoor lights from adjacent properties create a nuisance.
Compare other topics
See how Altadena and Norwalk compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool