Grading & Drainage: Altadena vs Santa Monica
How do grading & drainage rules compare between Altadena, CA and Santa Monica, CA?
Santa Monica has fewer restrictions than Altadena.
Altadena, CA
Los Angeles County
Hillside grading exceeding 2,500 cubic yards cut + fill requires a Conditional Use Permit in Altadena (CSD 22.306.060.B.2.b). Grading during the Oct 15 – Apr 15 rainy season is subject to Public Works erosion-control requirements.
View full Altadena rules →Santa Monica, CA
Los Angeles County
Santa Monica requires adequate grading and drainage for all development. French drain systems with minimum 12x12 inch gravel cross-section required for downspout/gutter connections through curb face. The stormwater utility fee funds the drainage system.
View full Santa Monica rules →Key Facts Comparison
| Fact | Altadena | Santa Monica |
|---|---|---|
| Code Section | Altadena CSD 22.306.060.B + LA County 22.140.240 | - |
| CUP Threshold | 2,500 cy cut + fill | - |
| Haul Route | Required ≥1,000 cy off-site | - |
| Rainy Season | Oct 15 – Apr 15 (extra controls) | - |
| French Drain | - | 12x12 inch gravel minimum |
| Stormwater Fee | - | Based on parcel BMU |
| BMU | - | 0.0637 for avg single-family |
| Storage Areas | - | Must have adequate drainage |
Highlighted rows indicate differences between cities.
Altadena FAQ
Do I need a permit to grade my Altadena hillside lot?
Yes — a Minor Conditional Use Permit is required for any hillside development, and a full CUP if grading exceeds 2,500 cubic yards total (CSD 22.306.060.B).
Santa Monica FAQ
Do I need a grading permit?
Generally required for earth-moving over 50 to 100 cubic yards or changes to existing drainage patterns. Small landscaping projects are usually exempt.
My neighbor changed their grading and water flows onto my property. What can I do?
Contact Santa Monica code enforcement. Redirecting drainage onto neighboring properties violates most municipal codes. The neighbor may be required to restore proper drainage.
Compare other topics
See how Altadena and Santa Monica 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