The 1-Acre vs. 5-Acre SWPPP Rule, Explained

Published August 13, 2026. Last reviewed August 13, 2026. Technical review: Jim Price, CISEC, CESSWI. Founder, Stormwater Compliant LLC.

Texas construction sites disturbing 1 to under 5 acres are "small construction activity": they need a SWP3 and a posted Small Construction Site Notice, but no Notice of Intent and no fee. Sites of 5 acres or more are "large construction activity" and must also file an electronic NOI ($225) and a Notice of Termination at close-out.

Both tiers need a plan. Only one tier files anything with TCEQ. That distinction is worth getting right in both directions, because paying a fee you do not owe is annoying and skipping one you do owe means building without authorization.

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Small vs. Large Construction: The Comparison

	Small construction 1 to under 5 acres	Large construction 5 acres and up
SWP3 (SWPPP)	Required, in place before construction begins	Required, in place before construction begins
Notice of Intent (NOI)	Not required	Required, electronically through STEERS
Application fee	None	$225 electronic, $325 paper
Site notice form	Small Construction Site Notice, TCEQ-20963	Large Construction Site Notice, TCEQ-20961 (primary operator) or TCEQ-20962 (secondary operator)
Also posted	Signed notice only	Notice plus the first page of the submitted NOI
Posting deadline	At least 2 days before construction begins	Before construction begins
Copy to MS4 operator	Required	Required
Inspections	Same schedule as large sites	Same schedule as small sites
Stabilization deadlines	Identical	Identical
Notice of Termination (NOT)	Not required	Required, within 30 days of final stabilization
Coverage ends	When the site reaches final stabilization	When TCEQ approves the NOT

If you take one thing from this page, take that table. It is the single most-referenced piece of information in the whole permit.

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Small Construction Activity (1 to Under 5 Acres)

You are in this tier if total disturbance is at least one acre but less than five, including everything covered in when a SWPPP is required in Texas: clearing, grading, stockpiles, haul roads, and support activity.

What you owe:

1. Develop and implement a site-specific SWP3 before construction begins. Not a template with your address typed in. A plan matching your actual drainage, topography, and construction sequence.
2. Sign and post the Small Construction Site Notice, TCEQ-20963, at least two days before construction begins. It has to be readable by the public and by any inspector from outside the fence, and it stays posted until final stabilization.
3. Provide a copy of the notice to the operator of any MS4 receiving your discharge. In San Antonio that generally means the City, and SAWS as co-permittee.
4. Inspect, document, and correct on the permit's schedule for the life of the project.
5. Reach final stabilization. No termination filing, but the obligation to actually stabilize does not go away.

That is the entire filing burden: one signed notice, posted early, copied to the MS4. No fee, no STEERS account, no submission.

The two-day posting deadline is the part that trips people. It is not "before the first inspection." It is two days before you start work.

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Large Construction Activity (5 Acres and Up)

Everything above, plus three things.

File the Notice of Intent electronically through STEERS. The NOI obtains your permit coverage and must be submitted before construction begins. The fee is $225 electronic, $325 on paper. Since September 1, 2018, electronic filing through STEERS has been the default; paper requires an electronic reporting waiver.

Do not leave the STEERS account until the week you need to file. New accounts start in probationary status pending a signed electronic signature agreement, which takes time you may not have. The walkthrough is in filing a Notice of Intent through STEERS.

Post the Large Construction Site Notice, TCEQ-20961, along with the first page of your submitted NOI. Secondary operators post TCEQ-20962 instead.

File a Notice of Termination within 30 days of achieving final stabilization on all portions of the site you are responsible for. This also applies on a transfer of operational control, or if you obtain alternative authorization.

That last item is the one that generates the most avoidable cost in this entire permit. Coverage, and every obligation attached to it, continues until the NOT is submitted and approved by TCEQ. Demobilizing is not terminating. See filing the Notice of Termination.

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What Does Not Change at Five Acres

A persistent assumption is that small sites carry lighter ongoing duties. They do not. Once you are regulated, these are identical at both tiers:

• Inspection frequency. At least once every 14 calendar days and within 24 hours of the end of a 0.5-inch-or-greater storm event, or the elective 7-day schedule if documented in your SWP3.
• Stabilization deadlines. Initiate by the end of the next work day where activity has ceased and will not resume within 14 days; complete within 14 days of initiation.
• Corrective action documentation. Fix it and write down that you fixed it, with dates.
• SWP3 amendments. The plan updates as the site changes.
• Recordkeeping. Inspection reports and the plan itself stay available on site.
• Final stabilization at 70% of native background vegetative cover.

The only real difference is the paperwork you file at the beginning and the end. The work in between is the same.

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The MS4 Copy Almost Nobody Sends

Both tiers must provide a copy of the site notice, or the NOI, to the operator of any municipal separate storm sewer system receiving the discharge. The SWP3 has to list those MS4 operators by name and address.

This requirement gets skipped constantly, largely because contractors are not sure who the MS4 operator is. In the San Antonio metro it is usually the City of San Antonio, with SAWS acting as co-permittee alongside the City and TxDOT. In unincorporated areas it is typically Bexar County.

It is a two-minute task and it is a documented permit condition. When an inspector asks who you notified and you have no answer, it establishes a tone for the rest of the inspection.

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The San Antonio Overlay

One local requirement applies to both tiers and is not in the state permit at all.

Under the City of San Antonio construction stormwater ordinance (2014-06-19-0472, approved June 19, 2014), SAWS enforces TPDES requirements locally as co-permittee with the City and TxDOT. A copy of your NOI or Construction Site Notice must go to stormwaterconstruction@saws.org at least 48 hours before construction-related activities begin.

Forty-eight hours, not two days after you start. It is one of the most commonly missed items in this market and it takes about two minutes.

Sites over the Edwards Aquifer Recharge or Contributing Zone have a much larger consideration: under Part II.C.5 of the permit, construction cannot commence until TCEQ's Edwards Aquifer Protection Program has approved the applicable Water Pollution Abatement Plan or Contributing Zone Plan. That is independent of your acreage tier and independent of your CGP coverage.

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Common Mistakes at the Threshold

Calculating acreage from the building footprint. Disturbance includes everything you scrape. Projects that look like 4.2 acres on the site plan land at 5.4 once staging and haul roads are counted, which moves them into the large tier and an NOI they never filed.

Assuming a phased project stays small. If your phases are part of one larger common plan, the plan's total governs. Three 2-acre phases are a 6-acre project.

Filing an NOI you do not owe. On a genuine 2-acre standalone site there is nothing to submit. Some contractors file anyway "to be safe," which costs $225 and creates an authorization they now have to terminate.

Posting the notice on the trailer door. It has to be readable from outside the site by the public and by inspectors. Inside a locked gate does not satisfy it.

Taking the notice down at substantial completion. It stays up until final stabilization.

Skipping the notice because the site is small. The Construction Site Notice is the cheapest item in the permit and among the most frequently cited. See the most common SWPPP violations on San Antonio job sites.

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Not Sure Which Tier You're In?

Send us the site plan and we will confirm the disturbed acreage, tell you exactly which filings you owe, and give you a fixed-price scope and timeline for the plan itself. If you are close to the five-acre line, that verification is worth doing before you file anything.

Request a quote or call (210) 776-6515. More about our SWPPP services, and the full permit walkthrough in our field guide to the TCEQ Construction General Permit.

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Sources

• TCEQ, 2023 Construction General Permit TXR150000 (PDF)
• TCEQ, Stormwater General Permit for Construction Activities
• TCEQ, Assistance Tools for Construction Stormwater General Permits