Only if your home sits close to one of the two mapped fault traces. The Baton Rouge fault and the Denham Springs–Scotlandville fault cross East Baton Rouge Parish east to west and move slowly. A Louisiana Geological Survey and DOTD study begun in 1980 mapped 139 damaged structures along the first and 38 probable sites along the second. Most Baton Rouge foundation damage is ordinary settlement, not fault movement.
Foundation Repair Baton Rouge checks for the fault pattern on every evaluation in north and south Baton Rouge, because the right answer is very different if it’s the fault.
Are there active fault lines in Baton Rouge?
Yes, in the sense that matters for a house: Louisiana Geological Survey (LGS) work describes the Baton Rouge fault and the Denham Springs–Scotlandville fault as a combined system that breaks the Prairie Terrace across East Baton Rouge Parish. They are not earthquake faults. LGS reports that they produce no detectable earthquakes, and their activity is inferred from cumulative damage to roads, slabs and walls near the fault traces. The movement is slow creep, not a sudden shake.
A 2012 LiDAR-based map of the Baton Rouge and Scotlandville fault traces by McCulloh and Heinrich is published by the Louisiana Department of Transportation and Development (DOTD) on its mapping server, so you can see whether your street sits near a trace.
Where the faults run
The original LGS/DOTD fault damage study, prepared with Durham Geological Associates, was dated June 1, 1981, and its mapping began in early 1980. Its findings, as we summarize them here, are older than most readers expect. We did not find a newer published count of damaged structures, so treat the numbers as historical and the pattern as the useful part:
- Baton Rouge fault — about 14 miles from the Mississippi to the Amite River, passing near Nicholson Drive, University Lake, Perkins Road, Airline Highway and Tiger Bend Road.
- Denham Springs–Scotlandville fault — about 12 miles between the same rivers, passing near Crown Avenue, Beechwood Drive, Winchester Avenue and Glen Oaks High School.
Both are growth faults, with the ground on the south side moving down relative to the north.
How fast they move
Over geologic time the Baton Rouge fault has offset the surface by up to 22 feet in about 80,000 years — roughly an inch every 400 years. Modern movement has been measured faster: about 0.3 inches per year at Woodlawn High School, and about 4 inches of offset between 1960 and 1970 at Glen Oaks High School. Groundwater withdrawal is believed to contribute, and regional subsidence has been measured at up to about 0.35 inches per year.
What fault damage looks like
The study documented a consistent signature:
- Cracks in streets and driveways following the fault trace, often with a visible step down on one side.
- Cracks in slabs and brick walls, with wall cracks typically sloping at about 45 degrees in a consistent direction.
- “Block shear” — bricks split through — and mortar joints separating.
- Carports and porches pulling away from the house.
The key tell is alignment: cracks in the house, the driveway and the street lining up in the same direction.
How it differs from settlement
Settlement is local to your lot and follows moisture: the corner with the downspout, the side on deeper fill. Fault movement follows a line across many lots. If your neighbors on the same line have the same cracks and the street is cracked in line with your driveway, suspect the fault. If only your back corner is low, it’s almost certainly settlement.
How to check whether your house is near a fault trace
- Look at the pattern, not one crack. Check whether cracks in the house, the driveway and the street run the same direction, and whether the street shows a step down on one side.
- Compare with neighbors on the same line. Fault damage follows a line across many lots; settlement is local to one lot.
- Check the mapped trace. Compare your address against the corridors named above, or the DOTD map of the McCulloh and Heinrich (2012) fault traces.
- Ask for a laser elevation survey. It shows whether the slab is tilting in one direction across the whole house, which is the fault signature, or only low at one corner.
- Compare with ordinary settlement. Our guide to house settling vs foundation problems and the signs of foundation problems cover the more common causes.
What you can do
Pilings stop settlement; they can’t stop a fault. Near a trace, the practical approach is to fix any settlement that is also present, re-level as needed over time, use flexible connections for plumbing where possible, and think carefully before adding on. A structural engineer’s opinion is worth having — see do you need a structural engineer.
Bottom line
Most Baton Rouge cracks are settlement, but homes near the two mapped traces can show fault damage with a distinct aligned pattern. For an evaluation that checks for it, call Foundation Repair Baton Rouge.
Sources: Louisiana Geological Survey / Durham Geological Associates, Baton Rouge and Scotlandville–Denham Springs fault damage study (June 1, 1981, via LSU Law Center archive); McCulloh, LGS field guide to the Baton Rouge fault (2008); McCulloh and Heinrich (2012), “Surface faults of the south Louisiana growth-fault province,” GSA Special Paper 493, mapped at Louisiana DOTD; LSU Law Center Coast project, “The Baton Rouge Fault.”