Grading & Drainage: Daly City vs San Mateo
How do grading & drainage rules compare between Daly City, CA and San Mateo, CA?
San Mateo has fewer restrictions than Daly City.
Daly City, CA
San Mateo County
Grading and drainage in Daly City are governed by California Building Code Appendix J (grading) as adopted in Title 12 of the Municipal Code. A grading permit from the Daly City Building/Engineering Division is required for cuts or fills exceeding the Appendix J thresholds, and all sites must direct drainage to an approved point of discharge without creating runoff onto neighboring properties.
View full Daly City rules →San Mateo, CA
San Mateo County
Grading and drainage in San Mateo are regulated under the city's building code (Title 23) and the NPDES Municipal Permit. Projects requiring grading permits must submit drainage plans. All projects creating or replacing 5,000+ square feet of impervious surface must meet stormwater treatment requirements.
View full San Mateo rules →Key Facts Comparison
| Fact | Daly City | San Mateo |
|---|---|---|
| Code basis | California Building Code Appendix J (adopted Title 12) | - |
| Permit trigger | Cuts >5 ft or >50 cy; fills >1 ft supporting structures | - |
| Foundation slope | 5% min slope-away within 10 ft (CBC §1804.4) | - |
| Hillside reports | Geotech + engineering geology on landslide complex | - |
| Discharge | Must reach approved storm drain or watercourse | - |
| Permit | - | Required for grading exceeding thresholds |
| Erosion Plan | - | Required for all site disturbance |
| Stormwater | - | Treatment at 5,000+ sq ft impervious |
| Code Reference | - | SMMC Title 23 |
| Public Works | - | 650-522-7300 |
Highlighted rows indicate differences between cities.
Daly City FAQ
Can I grade my backyard without a permit?
Minor grading below the Appendix J thresholds (cuts <5 ft and <50 cubic yards) is typically exempt, but the work still cannot redirect water onto neighbors or block existing drainage. Check with the Building Division before any cut on a sloped lot.
Can I drain my downspouts into my neighbor's yard?
No. Cal. Civil Code §3479 (nuisance) and CBC §J109 prohibit creating concentrated runoff that crosses property lines. Daly City requires drainage to be conveyed to a public storm drain, gutter, or approved on-site infiltration.
Do I need a soils report for hillside work?
Yes - properties on the Westlake/Northridge slopes or within the Mussel Rock landslide complex generally require a geotechnical investigation and an engineering geology report under Appendix J §J104.3 before a grading permit is issued.
San Mateo FAQ
Do I need a grading permit in San Mateo?
Yes, for earthwork exceeding thresholds established in Title 23. All site disturbance also requires an Erosion and Sediment Control Plan.
What stormwater requirements apply to my project?
Projects creating or replacing 5,000+ square feet of impervious surface must meet stormwater treatment requirements under the city's NPDES permit.
Who reviews drainage plans?
The Public Works Department reviews grading and drainage plans. Contact them at 650-522-7300.
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