It mostly comes down to one number: how much land you disturb. Here is the one-acre rule, the common-plan trap, and what coverage requires.
In Tennessee, whether you need a SWPPP comes down mostly to one number: how much land your project disturbs. If you are clearing, grading, or excavating, this guide explains the basic trigger and what to do next.
Construction that disturbs one acre or more of land generally requires coverage under Tennessee's Construction General Permit (NPDES permit TNR100000), which means preparing a SWPPP and filing a Notice of Intent with TDEC. Critically, this includes sites under one acre that are part of a larger common plan of development or sale, for example, a single lot inside a subdivision that, as a whole, disturbs an acre or more.
Answer a few questions about your site and get a field-ready SWPPP built to TDEC permit TNR100000, ready to review, sign, and submit.
Get startedIf your site is covered, you generally must:
Even if your individual lot is well under an acre, if the subdivision is a common plan of development disturbing an acre or more, your lot is typically covered. For eligible at-grade single-family lots, TDEC provides the CN-1249 homebuilder SWPPP form.
If total disturbance reaches an acre, you need coverage even if the building footprint is small. Driveways, staging, and grading all count toward disturbed area.
If your project disturbs less than an acre and is not part of a larger common plan, you may not need state permit coverage, but local erosion-control ordinances can still apply. Many Tennessee cities and counties have their own requirements, so check with your local building or stormwater department.
Often yes. If the subdivision is a common plan of development that disturbs one acre or more, an individual lot within it is typically covered even if the lot itself is under an acre.
The NOI (TDEC form CN-0940) is how you request coverage under the Construction General Permit. It is filed through the MyTDEC portal before construction begins.
Under the current Tennessee Construction General Permit, twice per calendar week at least 72 hours apart, plus within 24 hours of a rain event of half an inch or more.