California SWPPP inspection requirements

The short version
Rain trigger
Forecast-based Qualifying Precipitation Event (QPE): 50% or greater chance of 0.5″ or more in 24 hours
Post-rain deadline
Pre-storm inspection within 72 hours before a QPE, daily during, and post-storm within 96 hours if the site rain gauge measured 0.5″ or more
Routine inspections
Every 7 days
Permit
Construction General Permit (Order 2022-0057-DWQ)
Agency
State Water Resources Control Board (SWRCB)

How California handles construction stormwater

Construction sites in California disturbing one acre or more need coverage under the Construction General Permit (Order 2022-0057-DWQ), administered by State Water Resources Control Board. The 2022 CGP (effective September 1, 2023) replaced the old REAP system with forecast-based QPE inspections. Requirements scale with site risk level; reporting runs through the SMARTS portal. Inspections are conducted during scheduled site operating hours.

Inspector qualifications

Inspections must be performed by a certified Qualified SWPPP Practitioner (QSP); SWPPP preparation requires a Qualified SWPPP Developer (QSD), who must also perform monthly inspections.

Official sources

Common questions

What triggers a SWPPP inspection in California?

Under the Construction General Permit (Order 2022-0057-DWQ), inspections are keyed to forecasts: forecast-based Qualifying Precipitation Event (QPE): 50% or greater chance of 0.5″ or more in 24 hours. Pre-storm inspection within 72 hours before a QPE, daily during, and post-storm within 96 hours if the site rain gauge measured 0.5″ or more. Routine inspections: every 7 days.

Who can perform SWPPP inspections in California?

Inspections must be performed by a certified Qualified SWPPP Practitioner (QSP); SWPPP preparation requires a Qualified SWPPP Developer (QSD), who must also perform monthly inspections.

Who administers the construction stormwater program in California?

State Water Resources Control Board (SWRCB) administers the NPDES construction stormwater program in California under the Construction General Permit (Order 2022-0057-DWQ).

What are the penalties for SWPPP violations in California?

Federal Clean Water Act civil penalties can reach $68,445 per day per violation, and SWRCB can issue administrative orders and state penalties on top. Missing rain-triggered inspections is among the most commonly cited violations in stormwater audits.

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