SWPPP Requirements in Iowa

Who needs a SWPPP in Iowa?

Any construction project that disturbs one acre or more — or is part of a larger common plan of development reaching one acre — needs a SWPPP under Iowa permit General Permit No. 2.

Iowa runs its own delegated stormwater program. Operators obtain coverage from Iowa Department of Natural Resources (DNR), NPDES Section under NPDES General Permit No. 2 — Storm Water Discharge Associated with Construction Activities (General Permit No. 2), not directly from the EPA. A small subdivision, a solar pad, and a road-widening project all clear the same one-acre line.

Iowa adds requirements worth flagging early: Construction may not start until DNR issues an authorization; the NOI (DNR Form 542-1415), fee, and proof of public notice are submitted after the SWPPP is complete (Parts II.A, II.C, IV.A.1); Publish public notice at least one day in the newspaper with the largest circulation in the area, and submit the demonstration with the NOI (Part II.C.3); Include the NOI in the SWPPP; the SWPPP must comply with Iowa Code section 161A.64 and local sediment and erosion plans (Part II.C.1.g); For common drainage locations serving more than 10 disturbed acres at one time, provide a sediment basin with 3,600 cubic feet of storage per acre drained where attainable; otherwise sediment traps, silt fences, or equivalent controls on all sideslope and downslope boundaries (Parts IV.D.2.a.(2).i–ii); Preserve topsoil within the authorized area and minimize soil compaction unless infeasible (Part IV.D.2.a.(2).iii); Every contractor and subcontractor identified in the SWPPP signs the co-permittee certification before working at the site (Part IV.D.7); Notify DNR within 30 days of an ownership transfer and include the notice of transfer in the SWPPP (Part II.F); Report hazardous conditions to DNR and the county sheriff within six hours of onset (Part III.B); Submit a Notice of Discontinuation within 30 days after final stabilization (Part II.G).

What the plan must contain

An Iowa SWPPPis the site's compliance binder — the document an inspector opens first. It documents:

1. 1Site & project descriptionTotal and disturbed acreage, soils, slopes, and the sequence of construction.
2. 2Receiving waters & discharge pointsWhere stormwater leaves the site and the waterbodies it reaches.
3. 3Erosion & sediment control BMPsSilt fence, stabilized entrances, inlet protection, and stabilization measures.
4. 4Inspection schedule & recordsDated, signed inspection logs and the corrective actions taken.
5. 5Operator certificationThe SWPPP is signed by the legally responsible party before work begins.

Required and conditional BMPs

Filing your Notice of Intent

Submit the NOI (DNR Form 542-1415), the fee, and the public notice demonstration online through the DNR Stormwater General Permit database, or by mail to the Storm Water Coordinator, Iowa Department of Natural Resources, 6200 Park Ave Ste 200, Des Moines IA 50321 (DNR Form 542-1415, 08/2025; Part II.D).

A Notice of Termination closes coverage once the site reaches final stabilization. Keeping the SWPPP and its inspection records on site is what keeps a project clear of stop-work orders.

Inspection requirements

Inspect at least once every 7 calendar days (disturbed areas not yet stabilized with a perennial vegetative cover of sufficient density to preclude erosion) (GP No. 2 Part IV.D.4). Every inspection is dated and signed, and any failed control is corrected before the next storm.

How Iowa differs from the federal permit

Because Iowa administers its own program, the federal EPA Construction General Permit does not apply directly here — the state permit governs. Sites inside a regulated municipal storm sewer system may carry additional local ordinance requirements on top of the state permit.

Frequently asked questions