Does my site need a licensed professional even though my state allows self-preparation?
In Connecticut, New York, Oregon, Utah and Vermont the answer depends on the site: water within 50 feet, a steep slope, an engineered basin, the project type, or a state risk score can each move a 1–5 acre project onto the licensed-professional side.
The triggers, and why they repeat
Three of the five states ask a version of the same two questions — is there perennial surface water within 50 feet, and is any part of the site at 70% (35 degrees) or steeper. Oregon adds an engineered sediment basin or a formal erosion management plan, and an acreage ceiling. New York splits by project type rather than acreage: a single-family home or an agricultural building is one answer, a commercial development is another, with no acreage floor. Connecticut turns on whether a municipal land-use commission will issue a written approval.
Every one of those is a fact you can read off the drawings. None of them asks you to make a professional judgement, which is deliberate — if answering required an engineer, the answer would already be "you need an engineer".
Answer them before you buy anything
The wizard asks these questions before it will generate a document, and it records which answers the determination rested on. If your answers put you on the licensed-professional side, it says so and stops.
Questions people ask
- What counts as a steep slope?
- Utah's clause puts it at 70% — 35 degrees — or more. Read your own state's wording on its page; the numbers are not identical everywhere.
- What if I am not sure how far the water is?
- Measure it before you rely on a self-prepared plan. The 50-foot line appears in several permits and it is the single most common trigger in this group.
The states this question turns on
- Connecticut SWPPP requirements — Connecticut normally requires a licensed professional engineer or landscape architect to certify the plan, but a 1–5 acre project approved in writing by a municipal land-use commission is exempt from state review.
- New York SWPPP requirements — New York splits by project type, not acreage: Table 1 projects (single-family homes, residential subdivisions, agricultural buildings, underground utilities, trails) can be self-prepared, while commercial development and other Table 2 projects need a stormwater management practice component and therefore a licensed professional — with no acreage floor.
- Oregon SWPPP requirements — Oregon small sites can self-prepare by default; a stamp by a CPESC, CPSWQ, PE, RLA or CEG is required only when the site disturbs 20 acres or more, when a non-standard buffer compliance option is used because water is within 50 feet, or when an engineered sediment basin or erosion management plan is built.
- Utah SWPPP requirements — Utah requires a qualified SWPPP writer for a 1–5 acre site only when perennial surface water sits within 50 feet or the site has a slope of 70% (35 degrees) or steeper.
- Vermont SWPPP requirements — Vermont scores each site as Low or Moderate risk; Moderate-risk sites need an EPSC plan prepared by a certified engineer, while Low-risk sites need only a self-made site drawing.
Other questions
- Who can prepare a SWPPP?
- Which states require a licensed professional to prepare a SWPPP?
- Which states make you take a course before writing a SWPPP?
- What acreage thresholds change SWPPP requirements?
- Why does my state call it something other than a SWPPP?
Check your state and build a draft
The questionnaire and the generator run in your browser. Checkout is not open, so nothing can be charged.
Source: SwpppDraft 50-state preparer-requirement table, from a scan of all 50 construction general permits, read 2026-08-03. County and city rules are not covered.
What we are, and what stays your responsibility
- SwpppDraft is a document generation tool. It does not provide engineering services, legal services, or compliance consulting, and no engineer or attorney reviews what it produces.
- Everything in the document is built from the site facts you enter. Checking that those facts are right, and that the resulting plan fits your project, is yours to do.
- We do not file anything on your behalf, we do not certify or endorse your compliance, and we accept no liability for what happens when you use the document.
- State-level requirements carry the date we verified them. County and city rules are not covered — some local jurisdictions require a licensed preparer even where the state does not, and you have to check that yourself.
- When the product opens, our total liability will be capped at the amount you paid us. Today that amount is zero, because nothing is for sale.