LAState-AdministeredSWPPP Requirements in Louisiana
Louisiana's construction stormwater program under the LAR100000 LPDES general permit operates against a backdrop of extraordinary environmental complexity. The state contains nearly 40% of all coastal wetlands in the contiguous US, and virtually every construction project in southern Louisiana involves jurisdictional wetlands, coastal zone management requirements, or both. The Louisiana Coastal Management Division administers coastal use permits separately from LDEQ's LPDES program, creating a dual-permit environment for most coastal construction. Greater New Orleans presents unique challenges not found anywhere else in the US: below-sea-level elevations in much of the metro area mean that gravity drainage is impossible—stormwater must be pumped, and construction dewatering requires active pump systems rather than passive BMPs. Hurricane season from June through November is not a background risk but an operational reality that must be addressed in every SWPPP for Louisiana projects. Tropical weather systems can deliver 10–20 inches of rain in 24 hours, requiring pre-storm BMP reinforcement protocols and post-storm rapid-response inspection and repair procedures.
Louisiana SWPPP Key Facts
- ✓Louisiana contains ~40% of all US coastal wetlands—most southern LA projects involve jurisdictional wetlands
- ✓Louisiana Coastal Management Division coastal use permit required for most projects in coastal zone (separate from LPDES)
- ✓Greater New Orleans below-sea-level elevation requires pump-based dewatering rather than gravity drainage
- ✓Hurricane season (June–November) creates 10–20 inch rainfall events that overwhelm standard BMPs
- ✓$0 NOI fee; online submission through LDEQ's electronic reporting system
- ✓Army Corps Section 404 permits are needed for virtually any project involving wetland fill—Louisiana has more jurisdictional wetlands per square mile than any other state
- ✓Baton Rouge and Lake Charles are major industrial construction markets with petrochemical facility adjacency creating SPCC/SWPPP overlap situations
- ✓Louisiana's alluvial soils (Mississippi River delta) are highly erodible clay and silt that mobilize rapidly in rain events
Administering Agency
- Agency
- Louisiana Department of Environmental Quality (LDEQ)
- Phone
- 225-219-5337
- customerservice@la.gov
- Website
- LDEQ Stormwater Program
Permit Details
- Permit Name
- LPDES General Permit for Stormwater Discharges from Construction Activities
- Permit Number
- LAR100000
- Effective Date
- 2019-09-01
- Permit Document
- View Current Permit
SWPPP Thresholds & Triggers
- Acreage Threshold
- 1 acre of land disturbance, or less than 1 acre if part of a larger common plan of development
Louisiana's pervasive wetlands mean most construction projects encounter jurisdictional wetlands requiring Section 404 Army Corps permits and Louisiana Coastal Management Division coastal use permits. Below-sea-level elevation in Greater New Orleans area creates unique dewatering and stormwater management challenges. Coastal Zone Management boundary covers most of southern Louisiana.
Inspection Requirements
- Inspection Frequency
- At least once every 7 calendar days and within 24 hours of a qualifying storm event of 0.5 inch or more
- Rain Event Threshold
- 0.5 inch in a 24-hour period
- Certified Inspector
- Not required by state
Hurricane season (June–November) creates a unique risk profile in Louisiana—tropical weather systems can deliver 10+ inches in 24 hours, overwhelming standard BMPs. SWPPPs in coastal Louisiana should include hurricane season BMP protocols. New Orleans metro sites below sea level require pump-based dewatering systems rather than gravity drainage.
Penalties & Enforcement
- Max Civil Penalty (Per Day)
- $25,000 per day per violation
- Criminal Penalties
- Criminal penalties under Louisiana Environmental Quality Act RS 30:2025 for willful violations
LDEQ coordinates with Louisiana Coastal Management Division and Army Corps of Engineers on wetland and coastal construction compliance. Joint enforcement actions are common in coastal Louisiana where multiple permits apply simultaneously.
Permit Fees
- NOI Filing Fee
- $0
- NOT Filing Fee
- $0
- Other Fees
- Louisiana Coastal Use Permit fees vary by project type and impact level. Army Corps Section 404 permit fees may apply.
How Louisiana Differs from Federal Requirements
- ⚠Louisiana Coastal Use Permit requirement is a state-specific additional permit layer with no federal CGP equivalent.
- ⚠Below-sea-level site conditions in Greater New Orleans create de facto additional SWPPP requirements not addressed in federal CGP guidance.
- ⚠Hurricane season BMP protocols are Louisiana-specific operational requirements not covered in the standard federal CGP.
- ⚠Louisiana's pervasive jurisdictional wetlands create a near-universal Section 404/SWPPP dual-permit requirement not typical in other states.
- ⚠$0 NOI fee makes Louisiana one of the most cost-effective states for permit registration, though coastal use and Section 404 permits can be expensive.
SWPPP Tips for Louisiana
- ➤Engage Army Corps of Engineers and Louisiana Coastal Management Division early—coastal use permits and Section 404 permits often take 6–18 months and will drive your project schedule.
- ➤Include a hurricane season BMP protocol in your SWPPP: pre-storm reinforcement checklist, BMP removal procedures for high-wind events, and post-storm 24-hour inspection requirement.
- ➤For New Orleans metro projects, design your dewatering system before finalizing the SWPPP—below-sea-level sites require continuous pump operation during rain events.
- ➤Wetland delineation is not optional in Louisiana—assume any low-lying area is jurisdictional and have a delineation completed by a qualified wetlands scientist before project design.
- ➤Louisiana's subtropical climate means vegetation grows rapidly—use this to your advantage for temporary stabilization, but ensure seed mixes are appropriate for the region (Bermuda grass, bahia grass).
- ➤For petrochemical corridor projects (Baton Rouge to New Orleans), coordinate your SWPPP with any existing SPCC plans at adjacent facilities.
Louisiana SWPPP FAQs
Do I need both a Louisiana Coastal Use Permit and an LPDES permit?+
Yes for most projects in southern Louisiana. The Coastal Use Permit (administered by the Louisiana Coastal Management Division / CPRA) covers any activity within the coastal zone that may affect coastal resources. The LAR100000 LPDES permit covers stormwater discharges. Both must be obtained—they are independent programs with separate applications and timelines.
How do I handle stormwater management on a below-sea-level New Orleans site?+
Gravity drainage is not feasible for most Greater New Orleans sites. Your SWPPP must address pump-based dewatering with discharge to the local drainage system or an approved receiving body. Coordinate with the Sewerage and Water Board or local parish drainage authority for discharge point approval.
What should my SWPPP include for hurricane season?+
Include a hurricane preparedness annex covering: BMP reinforcement procedures when a tropical storm watch is issued, procedures for removing or securing temporary BMPs before high-wind events, post-storm 24-hour inspection and repair protocol, and emergency contact list for LDEQ notification if a major discharge occurs.
How does wetland permitting work in Louisiana?+
Any fill or disturbance in jurisdictional wetlands requires a Section 404 permit from the Army Corps of Engineers (New Orleans District or Vicksburg District depending on location). Louisiana's Coastal Management Division also requires a Coastal Use Permit for activities within the coastal zone. These are separate permits with separate applications, and the Corps permit process can take 6-18 months. Engage both agencies at the earliest stage of project planning.
Are there additional requirements for construction near petrochemical facilities?+
Construction near active petrochemical facilities in Louisiana's industrial corridor (Baton Rouge to New Orleans along the Mississippi River) may require coordination with the facility's existing SPCC plan. LDEQ may also require additional chemical spill prevention measures in your SWPPP if the construction site is within the drainage area of an industrial facility.
What are LDEQ's penalties for LPDES permit violations?+
LDEQ can assess civil penalties up to $25,000 per day per violation. Criminal penalties under the Louisiana Environmental Quality Act (RS 30:2025) apply for willful violations. LDEQ coordinates with the Army Corps and Coastal Management Division on joint enforcement, so a single discharge event can trigger penalties from multiple agencies simultaneously.
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