California
The stormwater permit for construction in California
California runs its own NPDES programme, so a state issued construction general permit governs. Below is what our engine can say about it, and where we have not read that permit, what it will not say.
Governing permit
Construction General Permit, Order WQ 2022-0057-DWQ (NPDES No. CAS000002)
- Issued by
- California State Water Resources Control Board (State Water Board)
- Permit number
- CAS000002
- Version determined against
- as published by the state agency
- Effective
- 2023-09-01
- Expires
- 2028-08-31
Who may prepare the plan
A credentialed preparer is requiredCalifornia requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
Qualifying routes
- California PE or PG (self-certify)
- Landscape architect, AIH hydrologist, CPESC or CPSWQ plus CASQA training and exam
A state specific training course or exam is layered on top of the qualifying credential.
The SWPPP shall be developed by a Qualified SWPPP Developer (QSD). No PE stamp mandate.
Does a site in California need coverage
Worked for a one acre site as a reference point. Change the acreage in the tool below and the answer, and its reasoning, change with it.
Coverage
Permit coverage required
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Determined against dataset version 2026-07-19.
Read these before you act on the answer
- Requirements below are what we have read and cited directly from Construction General Permit, Order WQ 2022-0057-DWQ (NPDES No. CAS000002), not the federal CGP. A category we have not yet transcribed from this permit is omitted here rather than assumed to match EPA's rule.
- This first pass covers the Order itself and Attachments D (Traditional Construction Risk Level Requirements) and D.1 (Risk Determination Worksheet) only. It does NOT yet capture: Attachment E/E.1/E.2 (Linear Underground and Overhead Project Type 1/2/3 requirements, which parallel but are not identical to the Risk Level 1/2/3 framework for traditional construction); Attachment F (Active Treatment System numeric effluent limitations); Attachment G (Passive Treatment Plan requirements); Attachment H (site- and watershed-specific TMDL numeric action levels/effluent limitations, which vary by named water body and are far more numerous than the two statewide NALs captured here); Attachment I (Ocean Plan ASBS exception conditions); or Attachment J (dewatering numeric action levels). The 2022 CGP eliminated the Rain Event Action Plan (REAP) that existed under the prior 2009 permit (verified below), so no REAP mechanics are described because none currently exist. Likewise, this permit does not define a calendar-date 'rainy season' or tie final stabilization to fixed dates (e.g., no October 1/November 15 deadline was found); stabilization timing is instead keyed to cessation of earth-disturbing activity (immediately, or within a 14-day non-resumption threshold) — this was affirmatively checked, not merely unverified. No fixed-day-count deadline for submitting a Notice of Termination after completing construction was located in the Order (unlike some other states' 30-day NOT rules); Section III.H describes termination conditions and a 30-day automatic-approval-of-processing clock, but not a deadline for when the discharger must file. QSD/QSP certification/training prerequisites (Attachment A/glossary and separate SMARTS training materials) were not reviewed in detail. The three final-stabilization verification methods (70% cover, RUSLE2, custom) are named but their computational mechanics were not extracted.
- California requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
- Basinwise does not perform the physical site inspections the permit requires. Those must be carried out on site by a qualified person.
How this answer was reached, step by step
- 1
Coverage threshold
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
- 2
Permitting authority
California. The state runs its own programme under CAS000002.
- 3
Preparer credential
California requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
What to do next
- 1. Confirm the governing permit. Read Construction General Permit, Order WQ 2022-0057-DWQ (NPDES No. CAS000002) directly. It is linked above, and it is the document an inspector will hold you to. California State Water Resources Control Board (State Water Board)
- 2. Settle the preparer question before you draft. Getting this wrong costs a redraft at best. The detail is on the credential page for this state. Preparer credential in California
- 3. Screen the site. Run the real acreage and receiving water facts through the tool below. You get the inspection frequency, the stabilisation deadlines and the filing path with the permit section behind each.
- 4. Read the requirements in full. SWPPP requirements in California
Screen a California site now
Runs in your browser. Nothing about the site is transmitted.
What people ask about the California construction stormwater permit
Do I need a stormwater permit for a construction site in California?
Permit coverage is triggered at one acre of land disturbance, and below one acre if the project is part of a larger common plan of development or sale that will ultimately disturb an acre or more. The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Who issues the construction stormwater permit in California?
California State Water Resources Control Board (State Water Board) issues Construction General Permit, Order WQ 2022-0057-DWQ (NPDES No. CAS000002).
Does California require a qualified preparer for the plan?
California requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
Keep the record California will ask you for
The screening is free. Holding the written plan and the retained inspection log is what the permit actually demands.