Iowa
The stormwater permit for construction in Iowa
Iowa 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
NPDES General Permit No. 2, Storm Water Discharge Associated with Construction Activities
- Issued by
- Iowa Department of Natural Resources (Iowa DNR)
- Permit number
- NPDES General Permit No. 2
- Version determined against
- as published by the state agency
- Effective
- 2023-03-01
- Expires
- 2028-02-29
Who may prepare the plan
No preparer credential foundNo preparer credential was found for Iowa. 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.
Iowa identifies this permit by sequence number rather than a state-prefixed alphanumeric code. Credential: no preparer credential; the permit contains no reference to a professional engineer, CPESC or licensure. It requires only that 'SWPPPs shall be prepared in accordance with good engineering practices' and defines qualified personnel by capability and knowledge.
No permit section cited. Confirm this with your permitting authority.
Does a site in Iowa 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 NPDES General Permit No. 2, Storm Water Discharge Associated with Construction Activities, 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.
- Iowa's General Permit No. 2 does not distinguish stabilization completion deadlines by acreage -- only a single 'immediately, if activity ceases permanently or is suspended >14 days' initiation trigger and a single Final Stabilization definition apply regardless of site size, so no fact was recorded for stabilization.complete.fiveAcresOrLess/moreThanFiveAcres. The permit does not offer a biweekly-plus-rain inspection alternative -- only a flat 7-day routine inspection interval, so inspection.routine.biweeklyPlusRain was omitted. No distinct increased inspection frequency for sensitive/impaired waters; Outstanding Iowa Waters are instead excluded from coverage entirely, so inspection.increased.sensitiveWaters was omitted. Iowa is not arid/semi-arid, so inspection.reduced.aridSemiAridDrought was omitted. No numeric turbidity or pH discharge limit was found; only a non-mandatory 80% TSS removal design goal and a 3,600 cubic-foot-per-acre sediment basin storage design standard exist. The NOI deadline is not a day-count before construction; the permit simply requires DNR authorization be issued before activities commence.
- No preparer credential was found for Iowa. 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
Iowa. The state runs its own programme under NPDES General Permit No. 2.
- 3
Preparer credential
No preparer credential was found for Iowa. 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.
What to do next
- 1. Confirm the governing permit. Read NPDES General Permit No. 2, Storm Water Discharge Associated with Construction Activities directly. It is linked above, and it is the document an inspector will hold you to. Iowa Department of Natural Resources (Iowa DNR)
- 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 Iowa
- 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 Iowa
Screen a Iowa site now
Runs in your browser. Nothing about the site is transmitted.
What people ask about the Iowa construction stormwater permit
Do I need a stormwater permit for a construction site in Iowa?
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 Iowa?
Iowa Department of Natural Resources (Iowa DNR) issues NPDES General Permit No. 2, Storm Water Discharge Associated with Construction Activities.
Does Iowa require a qualified preparer for the plan?
No preparer credential was found for Iowa. 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 Iowa will ask you for
The screening is free. Holding the written plan and the retained inspection log is what the permit actually demands.