Hattiesburg Drainage Guide: Soils, 811 & Rules (2026)

Updated October 25, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	What to know	Source
Rainfall	About 64.4 inches a year (1991 to 2020 normals)	Wikipedia (NOAA data)
Ridge soils	McLaurin series (type location Forrest County): loamy sand over loam or sandy clay loam, well drained	USDA NRCS
Downtown runoff	Most downtown stormwater flows to Gordon's Creek, then the Leaf River	WDAM
Leaf River record	34.03 ft at the USGS Highway 11 gauge, 1974 flood	Forrest County
Hattiesburg permits	Generally required to repair or alter a home; 2018 IRC	City of Hattiesburg
Unincorporated Lamar County	No structural codes outside city limits; flood permit for any structure needing a utility	Lamar County
Before digging	Mississippi 811 notice 3 to 10 working days ahead; ticket valid 14 calendar days	SB 2102 (2023)
Homeowner exemption	Only for hand digging under 12 inches on property you own	Miss. Code 77-13-5
Remodeler license	Required for improvements to an existing home costing more than $10,000	Miss. Code 73-59-1

How much rain does Hattiesburg get?

About 64.4 inches a year on average, according to the 1991 to 2020 normals compiled from NOAA and National Weather Service data. That's a lot of water for any yard to handle, and much of it arrives in heavy storms. When rain falls faster than the soil can absorb it, the excess either runs off or sits in low spots, which is why the same corner of the lawn floods every time.

What kind of soil is under a Hattiesburg yard?

Hattiesburg sits on the Coastal Plain where the Leaf and Bouie rivers meet, and its soils formed on old river and marine terraces. The McLaurin series, whose official type location is in Forrest County, is common on broad ridge tops and upper hillsides between the major streams. USDA describes it as well drained and moderately permeable, with a loamy sand surface and a subsoil that becomes loam or sandy clay loam with depth. Water moves quickly through the sandy top and slows in the heavier layer below, which can send it sideways downhill toward a foundation.

Other terrace soils in Mississippi are tighter. The Prentiss series, for example, has a dense fragipan 20 to 32 inches below the surface and a seasonal perched water table at 2 to 2.5 feet from January through March. A contractor should dig a test hole or two to see what your lot actually has before designing a French drain or a dry well.

Where does Hattiesburg's stormwater go?

Downtown, most of it flows into Gordon's Creek and on to the Leaf River. In 2020, business owners along the creek described erosion, and residents near Bouie Street in eastern Hattiesburg described flash flooding. The city council that year sought $300,000 in bonds for flood control, detention basins and creek improvements, and in 2026 it approved a grant application for a detention pond near Camp Street and South 19th Avenue, which council leaders said would hold water back from Gordon's Creek and the river. If runoff from a public street or ditch is reaching your property, that's a city issue to report. Water from your own roof and lot is yours to manage.

What about the Leaf River?

Yard drainage doesn't protect against river flooding. The Leaf River's record stage at the USGS gauge at Highway 11 is 34.03 feet, set in 1974. Hattiesburg, Petal, Forrest County, state emergency agencies, the USGS and the National Weather Service partnered on flood-inundation maps that show which areas would be under water at a given river level. If your property is in a mapped flood area, ask your city or county before adding fill or changing the grade.

Who handles permits?

City of Hattiesburg: The Department of Urban Development says a permit is generally required to repair or alter an existing residence, enforces the 2018 International Residential Code, and requires inspections before permitted work is covered.
City of Petal: Its building department issues permits and inspects building, electrical, plumbing and HVAC work inside the city.
Unincorporated Lamar County: The county says it does not inspect single-family construction and has no structural building codes outside city limits, but it requires a flood permit for any structure that needs a utility of any type.

Small yard drainage jobs may not need a permit at all, but anything that ties into the house's wiring, changes drainage onto other property or adds fill in a flood area should be checked first.

Do I need to call Mississippi 811?

Almost certainly. Mississippi's dig law, as amended by Senate Bill 2102 in 2023, requires at least three and no more than ten working days' notice before excavating. The markings and locate request number are valid for 14 calendar days. The law exempts people moving earth by hand less than 12 inches deep on property they own, so a French drain trench or buried downspout line isn't covered. Utilities generally mark only to the meter or property line, so private lines, like a sprinkler system or a line to a shop, are the owner's to find. If you hire a contractor, have it place the request in its own name.

What licenses should a drainage contractor have?

Mississippi Code section 73-59-1 defines a residential remodeler as anyone who, for pay, builds or supervises improvements to an existing residence costing more than $10,000, and those remodelers must be licensed through the Mississippi State Board of Contractors. A drainage job that size, or one bundled with other work on the house, should come from a licensed company. Separately, the Mississippi Department of Agriculture and Commerce requires a Landscape Horticulturist License for anyone selling landscaping services or setting plants, so a contractor who will also sod or replant should hold one. Ask for license numbers and verify them.

Questions to ask before you hire

Where exactly will the water go, and could it affect a neighbor?
Am I in Hattiesburg, Petal or unincorporated county, and does this job need a permit?
Is my lot in a mapped flood area?
Who places the Mississippi 811 request, and when?
What licenses do you hold, and what are the numbers?
What pipe, fabric and stone will you use, and how is the system cleaned later?

Common questions

Can I dig my own French drain without calling 811?

Only if you're hand digging less than 12 inches deep on property you own. French drains go deeper, so call Mississippi 811 at least three working days ahead.

Does Lamar County require a permit for yard drainage?

Unincorporated Lamar County has no structural building codes, but it requires a flood permit for structures needing utilities. Ask the county planning office about your specific project.

Does a drainage contractor need a state license?

A residential remodeler license is required for improvements to an existing home over $10,000, and landscaping or planting work requires a state landscape license. Verify any license number you're given.

Hattiesburg and Pine Belt yard drainage guide (2026)