Idaho
The stormwater permit for construction in Idaho
Idaho 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
Idaho Pollutant Discharge Elimination System (IPDES) Construction General Permit for Discharge Activities, Permit No. IDR100000
- Issued by
- Idaho Department of Environmental Quality (IDEQ), Surface & Wastewater Division, IPDES Program
- Permit number
- IDR100000
- Version determined against
- as published by the state agency
- Effective
- 2022-02-10
- Expires
- 2027-02-09
Who may prepare the plan
No preparer credential foundNo preparer credential was found for Idaho. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
No named or licensed credential is required to prepare the SWPPP. The permit only requires that site inspections be conducted by personnel who completed the EPA construction inspection course and exam, or hold an equivalent current inspection certification, or work under someone who does — an inspection-competency requirement, not a preparation credential. 'Qualified Person' is a self-attested knowledge/skills description, not an exam-based credential. A PE stamp is NOT generally required; the only engineer-specific requirement is narrow and scenario-based (attesting a licensed engineer designed any chemical treatment system the operator elects to use), and does not gate general SWPPP preparation.
Does a site in Idaho 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 Idaho Pollutant Discharge Elimination System (IPDES) Construction General Permit for Discharge Activities, Permit No. IDR100000, 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.
- No Idaho-specific 'increased inspection frequency near sensitive/impaired waters' provision found -- ID's only inspection-frequency increase is for sites discharging dewatering water, not sensitive waters, so inspection.increased.sensitiveWaters was omitted. Numeric effluent limits beyond the turbidity WQS-exceedance benchmark were not found in the permit body itself.
- No preparer credential was found for Idaho. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
- 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
Idaho. The state runs its own programme under IDR100000.
- 3
Preparer credential
No preparer credential was found for Idaho. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
Verified2022 Idaho IPDES Construction General Permit (Permit No. IDR100000), Appendix A definition of 'Qualified Person'; Section 6.3 (Training Requirements for Persons Conducting Inspections); Section 7.1-7.2 (SWPPP General Requirements/Contents); Section 9.1.11 (signatory/certification)Source
What to do next
- 1. Confirm the governing permit. Read Idaho Pollutant Discharge Elimination System (IPDES) Construction General Permit for Discharge Activities, Permit No. IDR100000 directly. It is linked above, and it is the document an inspector will hold you to. Idaho Department of Environmental Quality (IDEQ), Surface & Wastewater Division, IPDES Program
- 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 Idaho
- 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 Idaho
Screen a Idaho site now
Runs in your browser. Nothing about the site is transmitted.
What people ask about the Idaho construction stormwater permit
Do I need a stormwater permit for a construction site in Idaho?
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 Idaho?
Idaho Department of Environmental Quality (IDEQ), Surface & Wastewater Division, IPDES Program issues Idaho Pollutant Discharge Elimination System (IPDES) Construction General Permit for Discharge Activities, Permit No. IDR100000.
Does Idaho require a qualified preparer for the plan?
No preparer credential was found for Idaho. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
Keep the record Idaho will ask you for
The screening is free. Holding the written plan and the retained inspection log is what the permit actually demands.