Lafayette, LA Drainage Guide: Fill, 811, Licenses (2026)

Updated October 24, 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	62.81 inches a year at Lafayette Regional Airport (1991 to 2020 normals)	NOAA normals via Wikipedia
Surface geology	Peoria Loess 3 to 5 meters thick: clayey silt to silty clay	Louisiana Geological Survey
Natural drainage	Coulees such as Isaac Verot, Mine, des Poches and Ile des Cannes flow to the Vermilion River	Wikipedia
Floodplain fill	LCG adopted zero net fill in November 2017	LCG Floodplain Management
Before digging	Louisiana 811: free; two full business days' notice, excluding weekends and holidays	LA Secretary of State; 811 Before You Dig
Home improvement	Registration required for projects of $7,500 or more on existing homes	LSLBC
Residential license	Required for residential projects over $50,000	LSLBC
Public drainage	LCG Drainage Department; report issues through 311	LCG

Why do Lafayette yards hold water?

Three reasons stack up. First, the rain: NOAA's 1991 to 2020 normals for Lafayette Regional Airport average 62.81 inches of precipitation a year, with measurable rain on about 117 days. Second, the ground is nearly flat. Lafayette sits on the Prairie Terrace of southwest Louisiana, above the surrounding wetlands but without much relief. Third, the soil. The Louisiana Geological Survey's geologic map of the Lafayette quadrangle shows a cover of Peoria Loess, wind-blown silt three to five meters thick, described as gray to brown clayey silt to silty clay. USDA official soil series descriptions for loess soils on the terraces of this region, such as Frost and Coteau, describe slow to moderately slow permeability, and they report seasonal saturation close to the surface in winter and spring. Water that can't soak in and can't run downhill quickly just sits.

What does that mean for drainage design?

Moving water to an outlet usually works better than trying to soak it into the ground.
Pipe runs need careful elevation planning, because a flat lot gives little natural fall.
Dry wells and soakaway pits can fill with groundwater during wet months.
Surface fixes such as grading, swales and catch basins often do more than buried pipe alone.

Where does public drainage take over?

Natural channels called coulees, including Isaac Verot Coulee, Coulee Mine, Coulee des Poches and Coulee Ile des Cannes, carry runoff to the Vermilion River. Lafayette Consolidated Government's Drainage Department handles drainage improvements and maintenance in the parish, and residents can report problems through LCG's 311 service. LCG's concrete coulees are typically cleaned every other year; a 2024 contract covered about 48,550 linear feet. Incorporated cities such as Youngsville, Broussard and Scott also run their own drainage work, so call city hall if you live in one of them.

Can I bring in fill dirt?

Check first. LCG's floodplain management page says the state, parish and city all regulate floodplain development, and that zero net fill was adopted in November 2017 to preserve the floodplain's ability to store water. LCG sums it up as: if you bring one bucket of fill in, you need to take one bucket out. Contact LCG's floodplain administrator before raising a yard in or near a mapped floodplain.

Do I have to call 811?

Yes. The Louisiana Secretary of State explains that the state's Underground Utilities and Facilities Damage Prevention Law requires a locate request before excavation, and that the service is free to contractors and the public because member utilities pay for it. The standard notice is two full business days, excluding weekends and holidays, and marks remain valid as long as they're visible, up to 20 calendar days from the mark-by time.

What does Louisiana require of contractors?

The Louisiana State Licensing Board for Contractors defines home improvement as work on an existing residential structure, including repair, alteration and improvement, with a project value of $7,500 or more, and requires a home improvement registration for it. Residential construction or home improvement projects over $50,000 require a residential license. Electrical and plumbing work have their own rules. Check a contractor's credential on the board's website before you sign.

Questions to ask a drainage contractor

Where exactly will the water go, and how will it affect my neighbors?
What is the elevation at the start and end of the pipe, and at the outlet?
Is my lot in a floodplain, and does this plan add fill?
Who will submit the Louisiana 811 request, and when?
Which LSLBC registration or license do you hold?
What's warrantied, and for how long?

Common questions

What is zero net fill in Lafayette?

A rule LCG adopted in November 2017 for floodplain development: any fill brought in must be offset by removing an equal amount of storage, so the floodplain can still hold water.

Does a drainage contractor need a license in Louisiana?

The LSLBC requires a home improvement registration for work on an existing home valued at $7,500 or more, and a residential license above $50,000.

How much notice does Louisiana 811 need?

Two full business days, not counting weekends and holidays. The service is free.

Lafayette Parish, Louisiana yard drainage guide (2026)