Who is allowed to write your stormwater plan, and why the answer is not yes or no

This question decides whether the document you produce is your deliverable or a draft somebody else has to sign, which makes it one of the more consequential things to get wrong. It is also the question the rest of the market answers worst, usually by reducing it to a boolean that misrepresents nearly half the country.

Three independent axes

A yes or no cannot carry the answer because states vary along three axes at once.

1. Which credentials qualify. Georgia accepts six licences or the CPESC. South Carolina accepts three seals and explicitly rejects the CPESC. Knowing that a credential is required tells you nothing about whether the person you already employ holds an acceptable one.
2. Whether a state course is layered on top. California and Georgia require state specific training or an exam in addition to the underlying credential. Holding the licence is not the same as being qualified to prepare the plan.
3. What triggers the gate. Utah gates above five acres, Oregon at 20, so acreage decides it there. New York gates on plan scope instead: the requirement attaches only where the plan carries the stormwater management practice component, so an erosion and sediment control only plan has no preparer credential at all.

Four ways this gets answered wrong

1. Treating a regulator side credential as an applicant side one

Some qualifications belong to the people who REVIEW plans, not the people who write them. Michigan, the Virginia plan reviewer and the South Carolina certified plan reviewer are all regulator side. Seeing one named in guidance does not mean you need to hire somebody who holds it.

2. Treating a named role as a credential

A permit that names a responsible person is not necessarily requiring an external qualification. Colorado's Qualified Stormwater Manager and Arizona's Qualified Person are self attested: the permit assigns a responsibility, it does not gate who may hold it. Reading those as credentials leads operators to hire consultants they never needed.

3. Overstating the professional engineer requirement

Practice act citations are routinely stretched on this point. A PE stamp is not required as a general matter in Washington, Colorado, Arizona, Texas or most states with no preparer gate. Where a state does require a licensed engineer, it is because its own permit says so, and you should be able to see the section that says it.

4. Forgetting that state law is a floor

A state with no preparer credential can still sit under a local ordinance that imposes one. Cook County MWRD in Illinois is the example we keep coming back to. Checking the state and stopping there is not the same as checking.

The California case, since it is the one people search for

California requires a Qualified SWPPP Developer. A person qualifies either by holding a California PE or PG and self certifying, or by holding one of several other credentials, including landscape architect, AIH hydrologist, CPESC or CPSWQ, together with the state training and exam. Notably there is no PE stamp mandate: the QSD route is its own thing, and a PE is one way in rather than the requirement.

The QSD is a California term of art. It does not exist elsewhere, and looking for a QSD in Texas is looking for a role that has no meaning there. What can exist elsewhere is an equivalent gate under a different name.

What to do about it

1. Check your own state rather than carrying another state's answer across. Our register publishes each jurisdiction with the source we read it from, and marks the ones we have not confirmed as not verified rather than as clear.
2. Settle it before anybody starts drafting. Discovering it afterwards costs a redraft at best and an invalid filed plan at worst.
3. If a credential applies, use a generated document as a draft. It saves your credentialed preparer the assembly work. It does not replace their signature, and any tool suggesting otherwise is putting you at risk to close a sale.
4. Check the local ordinance as well as the state rule.