Los Angeles County, CA Environmental Rules: Stormwater Management (2026)
Key Facts
- SWPPP
- Required when directed by Building Official; must be approved before grading permit issued
- ESCP filing deadline
- October 1 annually, if grading won't finish before November 1
- BMP installation deadline
- October 15 annually
- Fine: missing SWPPP (small project)
- $50/day (1–10,000 cu yd)
- Fine: missing SWPPP (medium)
- $250/day (10,001–100,000 cu yd)
- Fine: missing SWPPP (large)
- $500/day (over 100,000 cu yd)
Summary
All grading in unincorporated LA County must comply with NPDES requirements: best management practices must be installed before grading begins and maintained until permanent drainage is in place, or daily fines up to $500 per day apply.
J110.8 National Pollutant Discharge Elimination System (NPDES) compliance.
J110.8.1 General.
All grading plans and permits and the owner of any property on which such grading is performed shall comply with the provisions of this Section for NPDES compliance.
All best management practices shall be installed before grading begins or as instructed in writing by the Building Official for unpermitted grading as defined by Section J103.3. As grading progresses, all best management practices shall be updated as necessary to prevent erosion and to control construction-related pollutants from discharging from the site. All best management practices shall be maintained in good working order to the satisfaction of the Building Official until final grading approval has been granted by the Building Official and all permanent drainage and erosion control systems, if required, are in place.
(Ord. 2025-0047 § 81, 2025.)
Full Breakdown
Section J110.8 requires NPDES compliance for all permitted and unpermitted grading projects. The Building Official may require a Storm Water Pollution Prevention Plan (SWPPP) as a condition of any grading permit. If grading will extend past November 1, the owner must file an Erosion and Sediment Control Plan (ESCP) with the county by October 1, with best management practices (BMPs) installed by October 15. BMPs must be maintained 'in good working order' continuously until final grading approval is granted. Failure to submit SWPPP/ESCP or install BMPs triggers escalating daily fines, and the county can enter the property to install controls at the owner's expense.
Violations & Fines
Missing SWPPP or ESCP: $50/day (1–10k cu yd), $250/day (10k–100k cu yd), $500/day (100k+ cu yd). Failing to install BMPs: $100/day (1–10k cu yd), $250/day (10k–100k cu yd), $500/day (100k+ cu yd). Failure to comply with ESCP can be treated as a grading security default.
Frequently Asked Questions
What is a SWPPP and when is it required for a grading project?
What are the annual stormwater obligations if grading continues through the rainy season?
What happens if I don't install stormwater controls on my grading site?
Sources & Official References
Other rules in Los Angeles County
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