What Is a SWPPP? Stormwater Pollution Prevention Plan Requirements on the Gulf Coast

Cynthia Henderson, PE, PWS
May 18, 2026
8:00 am

A SWPPP is a Stormwater Pollution Prevention Plan: a written, site-specific plan that shows how a construction site will keep sediment, fuel, concrete washout, and other pollutants out of stormwater leaving the site. It is required alongside coverage under a construction stormwater permit, which is issued under the Clean Water Act’s National Pollutant Discharge Elimination System (NPDES) program. This page covers what a SWPPP is, when one is required, how the requirements differ in Mississippi, Alabama, Florida, and Louisiana, what inspections the permits call for, and what a plan has to contain.

Cypress Environment & Infrastructure works from offices in Biloxi, Mississippi; Mobile, Alabama; and Pensacola, Florida. If you want help with a specific site, see our construction stormwater permit consultant page. For the broader program, see stormwater management.

SWPPP at a glance

What it is: a written plan for controlling erosion, sediment, and other pollutants during construction.
When it is required: generally when land disturbance is one acre or more, or when a smaller site is part of a larger common plan of development or sale that will reach one acre.
Who issues the permit: in Mississippi, Alabama, Florida, and Louisiana, the state environmental agency (MDEQ, ADEM, FDEP, and LDEQ).
When it is written: before the Notice of Intent (NOI) is filed or, for small sites in Mississippi and Louisiana, before construction starts.
What it requires afterward: routine and rain-triggered inspections, maintenance, plan updates, and records until the site is stabilized and coverage is terminated.

What does SWPPP stand for? SWPPP meaning

SWPPP stands for Stormwater Pollution Prevention Plan. Some permits and agencies write it as “storm water” (two words). The meaning is the same in every state: a plan that describes the pollution sources on a site and the controls that will be installed, inspected, and maintained to keep those pollutants out of stormwater.

In Alabama the same document has a different name. ADEM calls it a Construction Best Management Practices Plan (CBMPP). See SWPPP vs CBMPP below.

When is a SWPPP required?

The federal stormwater regulations require NPDES permit coverage for construction activity that disturbs one acre or more of land. They also cover smaller sites that are part of a larger common plan of development or sale that will disturb one acre or more in total, such as individual lots in a subdivision. Clearing, grading, excavating, and stockpiling count as disturbance.

The four Gulf Coast states run their own permit programs, so the permit that applies to a private project is the state’s construction general permit. EPA’s own Construction General Permit applies only where EPA is the permitting authority. Each state’s permit requires a SWPPP (or, in Alabama, a CBMPP). Points that commonly cause confusion:

Common plan of development. A single lot under one acre can still need coverage if it is part of a larger plan that will disturb one acre or more.
Large and small sites. Mississippi and Louisiana split construction permits at five acres, with different filing rules for the one-to-five-acre range.
Local permits. Counties and cities often add their own land-disturbance, erosion control, or stormwater permits. A state permit does not replace them.
Other permits. Construction stormwater coverage is separate from a Section 404 wetland permit, a Florida Environmental Resource Permit, and permanent stormwater design. A site can need several of them. See types of environmental permits.

A site under one acre that is not part of a larger plan usually does not need state construction stormwater coverage, but local erosion control rules can still apply.

SWPPP requirements by state

The permit names, thresholds, and filing rules below were checked against the issuing agencies’ published permits and web pages in October 2026. Permits are reissued and revised on a schedule, so confirm the version in effect for your coverage before relying on any detail.

Mississippi: MDEQ MSR10 and MSR15

MSR10 is the Large Construction General Permit, for land disturbance of five acres or more (including smaller sites in a larger common plan that will reach five acres). The current permit was reissued February 4, 2022, and expires January 31, 2027.
MSR15 is the Small Construction General Permit, for one acre to less than five acres (including smaller sites in a larger common plan in that range). MDEQ has stated that the permit was administratively continued past its April 30, 2024 expiration while MDEQ works on reissuance.
Large sites file a Notice of Intent with MDEQ, which MDEQ asks to be filed at least 30 days before construction, with the SWPPP and site drawings attached. Small sites complete a Small Construction Notice of Intent and develop a SWPPP, but submit them to MDEQ only if requested. Both must be kept on the site or locally available.

Alabama: ADEM ALR100000

ALR100000 is ADEM’s NPDES Construction General Permit. It applies to land disturbance of one acre or more, and to smaller sites that are part of a common plan of development or sale of one acre or more. ADEM published the reissued permit effective April 1, 2026.
A Construction Best Management Practices Plan (CBMPP) must be developed for every site before the NOI is submitted. It must be prepared and certified by a Qualified Credentialed Professional (QCP). The CBMPP is submitted with the NOI for priority construction sites, and ADEM can request it with the NOI for other sites.

Florida: FDEP NPDES Construction Generic Permit

The Construction Generic Permit (CGP), under Rule 62-621.300(4)(a), Florida Administrative Code, applies to construction that disturbs one acre or more, or less than one acre as part of a larger common plan, and discharges to surface waters or a municipal separate storm sewer system (MS4).
The SWPPP must be developed before the NOI is submitted. The NOI and fee are due at least two calendar days before construction begins.
FDEP has published a revised draft CGP (dated July 22, 2026) that would change inspection timing and inspector language. Until FDEP adopts it, the current permit governs.
CGP coverage is separate from an Environmental Resource Permit (ERP), which covers wetlands, surface waters, and permanent stormwater systems.

Louisiana: LDEQ LAR100000 and LAR200000

LAR100000 is the large construction general permit, for five acres or more (including smaller sites in a larger common plan that will reach five acres). LDEQ lists its term as October 1, 2024 to September 30, 2029. The operator files an NOI and the SWPPP is not submitted with it; by signing the NOI the operator certifies that a compliant SWPPP exists.
LAR200000 is the small construction general permit, for one acre to less than five acres. LDEQ lists its term as August 25, 2023 to August 24, 2028. It does not require an NOI or a fee. It requires a completed SWPPP before construction, a posted notice near the main entrance, and a completion report at final stabilization.
In both permits the SWPPP must be in writing, signed, certified, and implemented when earth-disturbing work begins.

SWPPP vs CBMPP (Alabama)

A SWPPP and a CBMPP do the same job: each is the site-specific plan that the state construction general permit requires. The difference is the name and some of the Alabama-specific rules.

Name. Alabama uses CBMPP. Mississippi, Florida, and Louisiana use SWPPP.
Credentials. In Alabama the CBMPP must be prepared and certified by a QCP. ADEM’s QCP definition includes a licensed Alabama professional engineer with appropriate erosion and sediment control training and a Certified Professional in Erosion and Sediment Control (CPESC), among other recognized credentials.
Timing. The CBMPP is developed before the NOI. The permit also requires a pre-construction inspection and periodic QCP evaluations of the plan on the ground.
Content. ADEM specifies a site-specific narrative, topographic maps, and erosion, sediment, and stormwater management control plan sheets.

If a project spans states, the plan has to follow the permit of the state where the work is located.

Who writes and signs a SWPPP?

The permit holder, meaning the owner or operator, is responsible for the plan. In practice, a consultant, engineer, or the contractor’s environmental staff writes it. The rules on who must prepare or sign it differ by state:

Alabama: a QCP must prepare and certify the CBMPP.
Louisiana: the SWPPP must be signed, dated, and certified as the permit’s signatory requirements describe. The permit calls for preparation in accordance with good engineering practices.
Mississippi: the permits call for a SWPPP prepared in accordance with sound engineering practices.
Florida: the permit calls for a SWPPP prepared following standard industry practices. Under the permit’s signatory rules, a responsible authority signs the SWPPP and related documents, and contractors and subcontractors named in the SWPPP sign a certification.

Whoever writes it, the person who signs the NOI or certification is certifying that the plan matches the site and the permit. A plan taken from a template and never adjusted to the site is a common source of violations.

What a SWPPP contains

Each state’s permit lists minimum contents, and the order and wording differ. Most plans include the following:

Site description. Project location, nature of the work, total and disturbed acreage, soils, and the receiving waters that the site drains to.
Site map. Drainage patterns, discharge points, surface waters and wetlands, limits of disturbance, and the location of each control.
Pollutant sources. Sediment, fuel and equipment fluids, concrete washout, paints and solvents, stored materials, and waste, with the control for each.
Erosion and sediment controls. Perimeter controls, inlet protection, construction exits, sediment basins or traps, slope protection, and stabilization methods.
Construction sequence. Controls installed before soil is exposed, and a schedule for temporary and final stabilization.
Inspection and maintenance procedures. Who inspects, how often, how rainfall is recorded, and how deficiencies are corrected.
Responsible parties. The owner, operator, and contractors, with the person responsible for implementation.
Plan updates. When and how the plan is amended as the site changes.
Termination. The stabilization criteria that must be met before a Notice of Termination or completion report is filed.

SWPPP inspection requirements

Inspections are where most compliance problems show up. The frequency depends on the state permit. Confirm the current permit terms for your coverage.

Mississippi (MSR10 and MSR15): after rain events that produce a discharge, and at least weekly for a minimum of four inspections a month, and as often as necessary to keep controls working.
Alabama (ALR100000): a pre-construction inspection, daily observations by site personnel, a full site inspection once each month for non-linear projects, and an inspection after any qualifying precipitation event (0.75 inches or more in 24 hours). For non-linear projects, the rain-event inspection begins no later than 24 hours after work resumes and is completed within 72 hours of the event. A QCP also evaluates the CBMPP on site at least every three months for priority sites and every six months for other sites. Site inspections are performed by a Qualified Credentialed Inspector (QCI), a QCP, or a qualified person under a QCP’s direct supervision.
Florida (CGP): at least once every seven calendar days, and within 24 hours of the end of a storm event of 0.50 inches or more, including weekends and holidays, by a qualified inspector the operator provides. Corrective actions must be completed in a timely manner and no later than seven calendar days after the issue is identified.
Louisiana (LAR100000 and LAR200000): at least once every seven calendar days, or at least once every 14 calendar days plus before anticipated storm events and within 24 hours of the end of a storm event of 0.5 inches or more. The SWPPP must state which schedule applies, and the operator must keep to it. Linear or remote projects have a separate option.

A missed inspection is a permit violation even if the controls look fine. If one is missed, inspect as soon as possible, document the gap, and fix any deficiencies.

Cypress performs stormwater compliance inspections in Baldwin and Mobile Counties, Alabama, and Escambia County, Florida, led by a Certified Professional in Erosion and Sediment Control (CPESC). Each inspection produces a written report, a dated photo log, and a corrective-action list.

Common construction BMPs

Best management practices (BMPs) are the physical and procedural controls the SWPPP names. The right set depends on soils, slopes, and where water leaves the site. Common examples:

Silt fence and other perimeter sediment barriers, trenched in and maintained.
Inlet protection at storm drains and curb inlets.
Stabilized construction exits to limit tracking onto roads.
Sediment basins and traps sized for the contributing area.
Check dams and stabilized channels in concentrated flow paths.
Temporary seeding, mulch, erosion control blankets, and sod to cover exposed soil.
Concrete washout areas, covered storage for materials, and spill kits.
Dewatering controls where groundwater or stormwater is pumped from excavations.

For types, installation details, and common failures, see erosion control BMPs.

SWPPP checklist

Use this as a starting list. It does not replace the permit.

Confirm total acreage, disturbed acreage, and whether the site is part of a larger common plan.
Identify the permit that applies (MSR10, MSR15, ALR100000, Florida CGP, LAR100000, or LAR200000) and the version in effect.
Identify the receiving waters and any wetlands, and check for local land-disturbance or MS4 requirements.
Prepare the site map, with drainage, discharge points, and control locations.
Identify pollutant sources and assign a control to each.
Set the construction sequence, with controls installed before grading.
Name the responsible parties and the qualified inspector or QCP/QCI, as the state requires.
Complete and sign the plan, and file the NOI where the state requires one.
Install controls and, where the state requires it, complete the pre-construction inspection.
Set up a rain gauge or other rainfall log, and an inspection schedule.
Inspect on schedule and after qualifying rain. Record findings and corrective actions.
Update the plan when the site, the sequence, or the discharge points change.
Stabilize the site, and file the Notice of Termination or completion report.
Keep the file, including the plan, reports, rain logs, and acknowledgments, for the period the permit requires (Florida’s CGP requires three years after final stabilization and Notice of Termination).

SWPPP compliance: records, corrective action, and termination

Compliance depends on records as much as on controls. Agencies review inspection reports, rain logs, and plan revisions during file reviews and site visits. The records should show that the plan matches the site as built, that inspections happened on schedule, and that deficiencies were corrected and the correction was recorded.

When the site reaches final stabilization, the operator terminates coverage with a Notice of Termination or the equivalent in that state’s permit. Leaving coverage open after the operator no longer controls the site leaves responsibility unclear. Civil penalties for Clean Water Act violations are set by statute and adjusted over time, and states can use stop-work orders and permit action. This page does not quote figures because they depend on the case and current law.

SWPPP Florida: what to know

For Florida projects, the SWPPP is part of the FDEP Construction Generic Permit. The plan is developed before the NOI. The permit requires inspections at least every seven calendar days and within 24 hours of the end of a 0.50-inch storm event, and it requires a qualified inspector. County and municipal rules can add requirements. Escambia County and the City of Pensacola, for example, have their own land-disturbance and stormwater permit processes that apply alongside the state permit. CGP coverage does not authorize wetland impacts or permanent stormwater systems; those fall under the ERP and, where the Corps regulates the feature, a Section 404 permit.

How Cypress helps

Cypress Environment & Infrastructure provides NPDES and construction stormwater permitting, stormwater design, and stormwater compliance inspections. The work on a construction site usually falls into three parts:

Plan and permit path. Determining which permit applies, preparing the SWPPP or CBMPP, and assembling the NOI. See construction stormwater permit consultant.
Inspections. Routine and rain-event inspections in Baldwin, Mobile, and Escambia Counties. See stormwater compliance inspections.
Related programs. Cities and counties that hold an MS4 permit have their own program obligations. See MS4 permit compliance for Gulf Coast cities.

SWPPP FAQs

What is a SWPPP?

A SWPPP is a Stormwater Pollution Prevention Plan. It is the written, site-specific plan that a construction general permit requires. It identifies pollution sources on the site, the controls that will manage them, and the inspection and maintenance procedures that keep the controls working.

What does SWPPP stand for?

Stormwater Pollution Prevention Plan. Older permits and some agencies write it as “storm water.”

When is a SWPPP required?

Generally when construction disturbs one acre or more of land, or when a smaller site is part of a larger common plan of development or sale that will disturb one acre or more. The state construction general permit sets the specific requirements. Mississippi and Louisiana have separate small-site permits for one to less than five acres.

Who writes a SWPPP?

The owner or operator is responsible for it, and a consultant, engineer, or contractor usually prepares it. In Alabama, the CBMPP must be prepared and certified by a Qualified Credentialed Professional. Other states set different signature and certification requirements.

What is the difference between a SWPPP and a CBMPP?

They serve the same purpose. Alabama calls the plan a Construction Best Management Practices Plan and attaches Alabama-specific credential and timing rules. Mississippi, Florida, and Louisiana call it a SWPPP.

How often does a SWPPP site need to be inspected?

It depends on the state. Florida requires inspections at least every seven calendar days and within 24 hours of the end of a storm event of 0.50 inches or more. Louisiana (LAR100000 / LAR200000) requires either (a) at least once every 7 calendar days, or (b) at least once every 14 calendar days, before anticipated storm events, and within 24 hours of the end of a storm event of 0.5 inches or greater — the SWPPP must pick one schedule. Mississippi requires inspection after rain events that produce a discharge and at least weekly (minimum four per month). Alabama requires monthly full site inspections plus rain-event inspections after 0.75 inches or more in 24 hours. See the inspection section above and confirm the current permit.

Does a SWPPP replace a Section 404 permit or an Environmental Resource Permit?

No. Construction stormwater coverage addresses stormwater discharges during construction. A Section 404 permit addresses fill in regulated waters, and a Florida ERP addresses wetlands, surface waters, and permanent stormwater systems. A site can need more than one.

Do I need a SWPPP if my site is under one acre?

Often not, if it is a stand-alone site. If it is part of a larger common plan that will disturb one acre or more, coverage usually applies. Local erosion control or land-disturbance permits can apply to smaller sites.

Talk to Cypress about your site

If you are starting a project, renewing coverage, or catching up on inspections, contact us or call 228-596-1580. Send the site address, disturbed acreage, the state, and any existing permit number, and we will review the coverage path, the plan needs, and the inspection scope.

Offices: Biloxi, MS · Mobile, AL · Pensacola, FL.